November 19 1965NEWSLETTER MO. 4

THE CATCHUP ACOUSTICAL SOCIETYAs announced in the last issue,, a concert was «ivan at thn vw vm«in New York City on.. May 20,1965 at. whi* the S/vioJin fa^iD "~"all eight members — was presented toj the public^ The r,"*>"t %««-_-,

"Consort for True Violins",, compose d^anf^^edby HenlHr^tThe music gave each of the instruments a real, work-out, cSISLtheir musical potential in various combinations of parts a^d fSfm^fromsolo, duo, and trio to a thick texture of the entiri oatet? lhe"fffS?ne'w^^iSfeed^?!B!.^:^ 00t-" °f **«»"« %&£*£*£Leopold Stokowski was in the large audience, and was del igbtS'd Hetold Louis Condax that he would never forget the sound of thf viola in

The New York Times' Howard Klein quoted Maestro Stokowski ?s"We need to revise all. the orchestral instruments. The strings haveneeded this treatment for a long time. Now the woodwinds nS! motIL--1 Z _LXi^ o

In his review of May 21 „ 1.Q65,. Mr. Klein went on to say- "The

ha-^,

produced wonderful rumblings, and the sonorities of. the Mgher viol fesc.foodThrpe .food m high registers. The resonance of the middle rln^e lis M¥?J£& lnst"ent3 > whef paying their lowest notes, soundfd tiLTor nasal, so there is work to be done. But a major step toward rwSvat'n*the strings for the first time in 200 years has been tLen?!f aSi bravo^weref msiola*8 who Vl^* «» new instruments in their premiere concert

Max Pollikoff __Treble vjolinLrnestine Briemeister — Soprano violinLllla Ealman — Mezzo violinlll^L^yf - A"?.^?l^ (vertical viola)Peter Rosenfeld

Joseph TekulaDavid WalterStuart Sankey

Tenor violinBaritone violinBass violinG ontrabass viol in

Many members of the Catgut Acoustical Sooiaty, who have actuallyshared m the work of developing these instruments over the past sev-nyears, were in the audience. Interested musicians came from far and nearOne violinist, Marie Bond Riggenbach, flew all the way from her homem Monte Vista,^Colorado,^especially for the concert.

We have received a great deal of other publicity as well . To brino-up-to-date what was reported in the last Newsletter%(1) Carleen Hutchins spoke to the Acoustical Society of America at itsJune meeting in Washington, B.C. This included a presentation of thenew family of eight instruments. These were judged of particular inter-est to this group because they represent the first time in history t*ata consistent theory of acoustics has been successfully applied to awhole family of musical instruments,,

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(2) Publication in the American String Teacher of*(a) "The Catgut Acoustical Society Involved in Improving StringedInstruments", Spring 19.65, John Schelleng

(bj "The New Violin Family", Spring 1965,, Carleen Hutchins(c) "Three Firsts for the New Violin Family", Summer 1965, o.Hutchins(d) "The Hazards of Weather on the Violin", Fall 1965,Robert Fryxell

(3) The Princeton University Press has expressed interest in a publish-ing program which would include (a) the original writings of Savart withtranslations by Donald Fletcher (as discussed in Newsletter N0.2)(b) Frederick Saunders published papers, and (c) other research, papersin this field. In addition they are interested in a book on violinresearch which would encompass all of the efforts of our Societymembers. John Schelleng and Carleen Hutchins are already involved ina start on this project.(4) Heinrich Roth, of Scherl Roth in Cleveland,, has already arranged tohave six vertical violas made from Maxwell Kimball's drawings in theRoth shops in Germany. These are to be finished except for plate tuning,which will be done by Carleen Hutchins. As this is being written, shehas just received the first instrument from. Mr. Roth.

With all of this expanding activity and publicity, it is clear thatwe, as the Catgut Acoustical Society, both individually and collectively,are making our mark on the musical world. This brings with it anincreasing responsibility which 'requires added efforts on the part ofall of us, both in time and in financial, resources. As one example,previous Newsletters have been published in quantities of 150, nearlythree times the number needed to satisfy our current membership; yetalmost all copies have been sent out to others who have expressedinterest and who are in a position to aid in furthering our objectives.The present issue will be published in a quantity of 250 in anticipationof the increasing number of interested musicians and scientists.

Since we are "getting known",, your Executive Committee has drawn upthe following "Requirements for Membership" with no intent to destroyour informal nature, but merely to codify what we believe is a reason-able minimum of regulations — a sort of thing which any organizationmust have as it grows. This statement, together with "Aims of the CatgutAcoustical Society" published in the last Newsletter, constitute ourcharter and is the information which will, be sent out to any who expressinterest in our activities.

REQUIREMENTS FOR MEMBERSHIPTo be eligible for membership in the Catgut Acoustical Society, a

candidate must subscribe to the aims of the Society, as set forth inNewsletter N0.3, and express tangible interest therein. Suitableexpression of such active interest may be either direct aid in carryingout musical and technical projects or a monetary contribution towardsdefraying expenses of printing, postage,, etc. Although both types ofsupport are equally valued, and although there are no official dues,,it is hoped that members will find it possible to share in the latterway, if only modestly. Names will be removed from the membership listafter three years of complete inactivity. This requirement goes intoeffect with this issue of the Newsletter and is not retroactive.

Any member may sponsor a candidate for membership by sending name,address and qualifications to the Secretary: Carleen Hutchins, 112 EssexAvenue, Montclair, New Jersey. A list of proposed members will be

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within six months of publication! y ln good ate^i*S

Newsletterb^«8y1«£ he ?b<Te S li7t7d~"in the" last" ~

newsletter are hereby elected to membership. They are-Dr'Earll ?"£SJ» iVS"*11 Road - New Jersey«rpS^ ,

1?A00mi^" Slkhart, Indiana V

SrWT^!!" 1' ll£ MaSnolia Lane, Princeton, New Jersey, Dr. W. Lottermoser, Braunschweig, Germany"Jersey

riS/f^ 8011'^111*^Washingtol ' N' V'Y ' '

2"WE laH^ S aSL^Stitute of Cleveland, Ohio

2tS°idwM^ Si?g? SS*? K&*$£» ont -Sanitorium;London,Ont.

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(inWI le

at?efto'carl^Hutchins)^"! SHd*' *""" ""-^ Sa °krisonWashington last spring and on eacA of these t^ °°*oerts in (State of)on the viola*. I demonstrated ??»?+£», I ed a group of piecesConference at PortllSd in f^?i Mvl,oc .^sic Educators National(Robert Whitcomb) hM written a'bXtif^ T* oomP^er-in-re Sidenceand piano which { n&^gS^^Tg 1 01*falls m love with this v-ini^ t d iw ! Play> the audienceprod^e some. I oouid sell a hundred^? thef iS going toteaohers see at once the value nf ?hs = !m* Tht Publl ° school musicment, and they would l^to have fplrt oS^raf L^"0* 11* instru"violas are availahl p t q" „„,„„! * i 8 orcne stras. As soon as theschool inst^ttoS.« 80US t0 Start a West Coast olass for public

(LAa7=ioie"R^01?" 7 made by R.Parramon of Barcelona re-strung"i" SMJS" (vertioal viola) ' Cea

drI ?g!£«

niT

M6 foilowinS new candidates are proposed for membership( } On^^wl^ Bfrti?^» 989 Memorial Drive, Oxbridge MassContributed valuable editorial assistance cUUOXIa=e » Jttass.

(2) Dr.Bernard pickstein, 605 National Building, Flint Miahi«n'Amateur. violinist and string instrument enthusiast I,ilChlsan

Bassist,- helping to demonstrate the new instruments(4) Miss Mar jorie.Bram, 332 Vose Avenue, South Oran-e New Ter-^v

Music", a group performing on a consort of viols V(5) Mr. and Mrs. Quincy Porter, Holderness, New HampshireComposer, violinist, violist(6) Mr. David Schwartz, 26 Gurley Road, Stamford, ConnViolist, Yale School of Music

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(7)pßr!l°iP? N Dyer II The L.C.L. C0rp., 230 Park Avenue, N.Y.C,Interested in the new violin family; active in supporting andfollowing its progress. IIS ana

(8) Vi;i?S?3 uthier Lodge", l46l. Rosecrans, San Diego 6, Cal.Violinist,, violin maker,, and president of Southeri CaliforniaAssociation of Violin Makers. oainornia

TREASURERS REPORT:Balance reported in Newsletter N0.2as of 9/20/64.Four contributions

Expenditures:Reprints, "Physics of the Violin" $20.00Postage 25.00Newsletter expenses 33! 00Photographs for Newsletter lo.'ooBank service charge, l2 months 8.60YMHA Concert 5/20/65 82 6$

$120.10150.00

#2*70.10

179.22Balance, 9/20/65 * o0 30"We are happy to record the anonymous gift of $100.00 from one

ai^ent£v? iaS t:LO a*>°ut the advancement of research in the familyof stringed instruments. It is very likely that with the increatin-interest in the new instruments that costs will also increase AlsSthe requests for Newsletters far exceeds that of the memberb! # Until' sucha time as a grant will provide these costs, donations are earnestlysought from our members. There are no dues. May I urse that youcontribute to this undisputedly worthy cause." * ySincerely,Virginia Apgar, Treasurer.30 Engle StreetTenafly, New Jersey

As promised m the last Newsletter, this issue will presentcontributions from members which we hope you will find both interestingand instructive. First, however,, youreditor offers a brief historicalarticle describing the life and work of the late Fred„L. Dautrich!ic is the intent that future Newsletters will occasionally includesimilar items. '

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A CHAPTER IN THE HISTORY OF THE VIOLIN FAMILYLack in the 16th century, when viols were in their heyday,

the need and desire for instruments with bigger tone and greaterflexibility in tone color led to the gradual evolution of theviolin family. We now have the violin, viola and cello as thepopular instruments, and correspondingly, the viols have longsince fallen into relative disuse. Hoy/ever at several timessince the violin family emerged, there have been serious attemptsto enlarge the violin family in order to combine the versatility of rangeof -uhe viols and the versatility of tone color of the violin.

The first such proposal was described by M. Praetorius in hisSYNTAGMA MUSICUM: DE ORGANOGRAPHY published in 1619. Later, othersincluding Savart and Vuillaume also addressed themselves to thisproblem. In recent times, Dautrich and Hutchins each successfullydesigned and produced an enlarged series of violin-type instruments.Of the Hutchins instruments, we are currently witnessing theirintroduction to the musical world, as we have reported in pastnewsletters.

A history of these developments needs writing. It is intended thatthese newsletters provide the medium for recording all availableinformation, first as a matter of interest to our readers, and second,as a basis for a subseq uent larger article for broader circulation.To start off, this issue will tell the story of Fred L. Dautrich. Youreditor expresses his great appreciation to Mrs. Jean L. Dautrich for theloan of countless brochures and newspaper clippings from her familyarchives and for much additional personal help and information.

First, the man. Fred L. Dautrich was born in Schlierbach bei,7&chtersbach, near Frankfort am Main in Germany, the youngest of twelvechildren in a family of artists and artisans. At the age of twelve he".vent to Frankfort and worked as an apprentice at cabinet making untilhe was seventeen. Since he was an ardent pacifist, he left Germany atthis age to avoid military service. Together with a sister, he came tothe United States and settled in Connecticut, where three brothers hadpreceded him. For. a while, he held various jobs and studied art forwhich he had a great talent.

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But after a year and a half, he had abreakdown which necessitated a complete change. He went West andthus started a series of moves and travels which. took him tomany oartsof his .adopted country. Most significant was his acq uaintance withMrs. Delia Burnham of Orange, California, fur whom he worked as agardener. Kfcen she discovered his talent as a painter, she insistedthat he attend art school. This he did, in the art department ofColorado College in Colorado Springs until her death, and later at theSchool of Art and Design in Los Angeles, thus carrying out her wisheswith the money she had left him.

Through these years his interest in music grew, and with his abilityas a cabinet maker, he became proficient in repairing and re-graduatingold violins. He returned East, to Huntington, West Virginia, where hebecame director of a church choir. Here he married and soon the illnessof his wife again took him West, to California, thence to Idaho, andeventually to Tacoma, Washington. It was here that his plan took shapefor enlarging the violin family. Two new instruments were finished and"uried out here, and they received a very favorable reception.

He later returned to Torrington, Connecticut, where during the 1920' sand 1930' s he continued his studies and experiments with violin-typeinstruments, ar. work which culminated in a family including three new

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sizes of instruments. Two of these he called the Vilonia and Vilon,which are designed to play alto and tenor parts; the third is tneVilono which in size lies between the cello and bass viol.

The following notes on the instruments are given in Mr . Dautrich 's

own words, and are extracted from his brochure "Bridging the Gaps m the

Violin Family" (1935) and his article "Three New I"strume^"^f^ rNTo TViolin Family" which appeared in the October 1935 issue of THE VIOLiNIoT(pages 12-13;.

"Before the perfection of the violin type of instrument, the Viols

were the most practical form of bowed stringed instruments in use,ranging from those smaller than a violin to the size of the bass. v 40..40. .Chests of these viols, usually consisting of one of each size were used

in the fourteenth and fifteenth centuries."Because of their peculiarities of tone and tuning and the difficulty

of playing caused by the many strings used, the viols lost favor, andthe use of the instruments of the violin family increased. Ao finer

violins and cellos were made," the viols practically disappeared xrom use.

"The more practical tuning of the instruments of the violin family,

using four strings tuned' in fifths, offered a new field for both musicianand composers. More difficult and more beautiful music could be writtenand played on instruments of the violin family. String quartets

■

consisted of two violins, one viola and one cello, and these instrument

were used as the foundation of symphony orchestras."Although the violin and the cello reached their present state cf

perfection over 200 years ago, the viola has not been so rortunate.When made large enough to produce a fairly satisfactory tone it is

almost Impossible to play It under the chin, and when made smaUei,barely larger than a violin, the quality of tone is very much lika.that produced on a reasonably good half -sized violin.

"In modern chamber music, string ensemble and orches bra music , the

first violin, which is a soprano instrument, takes the leading par..Next comes the second violin playing the alto part, although It J-identical in size and tuning with the first violin, and must thereforebe a soprano Instrument incapable of producing a tone of ti^_altoquality.

"The tenor parts are taken by the viola, under-sized even for Its

tuning, which is alto, and yet it is expected to play the tenor parts.

No matter what £art the viola is given to play. It can never by mo c

than an under-sfeid alto instrument, tuned an octave above tne cello.

Where then is the tenoF"instrument? It should be made and tuned tx

taKTTEs place between' the viola and the cello, moving the viola up t.

take the alto part, in place of the second violin. But the viola Is .oosmall even for alto, and should be made the proper size for its pi cm.

"Composers, players and conductors have long wished for a bassinstrument having a finer tone and greater possibilitiest^an the bass viol. Such an instrument should be mace and tunedbetween the cello the bass viol to fill the gap that now exists

8"THE FIRST VIOLIN takes the first part in string ensemble and most

orchestrations. Much playing is done on the ule^^^n &

the most from an instrument, its entire range shou.d be udeu " J^ft-h« vilonia vilon, and vilono in the ensemble, it is no*r possioit _l-

he toS the best use of its entire range as we use nosecond violin; instead we use a true alto instrument "s^4^fviolin be alto when.it is tuned like the first, which is aop.snc;

7

4-t

"THE VILONIA, a true alto instrument, is tuned like the ordinaryviola, but it has the proper proportions for this tuning. The violahas never been so proportioned, which accounts for it peculiaritiesof tone. If the viola were tuned correctly for its size, it wouldbe only one or two tones lower than the violin. Makers of other musicalinstruments have long ago proportioned their instruments for the tonesto be produced; but of the violin family, only the violin and cello havebeen so proportioned.

"My vilonia is played between the knees in the manner of the cello,with the cello method of fingering. Many people claim that it jsav/kward to play an instrument between the knees; but where is there aviolinist who does not remember his first attempts to hold the violin?Does the cellist seem handicapped by the position of his instrument?As a solo instrument, especially for ladies, the vilonia fills a longfelt need. It is tuned in fifths, C,G,D,A, one octane higher than thecello. This gap of one octave is quite large, so I use a true tenorinstrument. (Can the viola be tenor when it is but a few tones belowthe violin, the soprano, and an octave higher than the cello?),,

"THE VILON, the true tenor instrument, is made to fill the gap ofone octave between the vilonia and the cello. It is tuned GDAE, oneoctave below the violin, a fifth higher tha n the cello and iscorrectly proportioned .for this tuning, the tone being full and roundsThe cello method of fingering is also used on this instrument,which is played between the knees. The use of the vilon will produceeffects that cannot be obtained on any other instrument.

"THE CELLO is the bass instrument of the string quartet and iscorrectly proportioned, well known to all as an ensemble, orchestra,and solo instrument. This instrument is tuned C,G,D, A^ with a full andpleasing tone of considerable power. In some forms of music, it isnecessary for the cellist to play very high on the A string in anattempt to fill the large gap between the cello and the higher stringedinstruments. With my Vilon in the ensemble, such gymnastics may bedispensed with.

"To my ear, there is. a great difference between the tone of the celloand the bass viol. To fill this space I have made another new instrumenTHE VILONO is the new bass, to be used in quintet and all other formsof music where this type of tone is desired. It is tuned G,D,A,E, twooctaves below the violin, one octave below the vilon, and a fourthbelow the cello. The cello- method of fingering is used on thisinstrument. The tone is much more pleasing for quintet than that of£he common "bull fiddle", having more of the smoothness and roundnessof the cello. For solo work, the vilono is of course less flexiblethan the cello. But an able player can play solos that would beimpossible on the bass viol.

"THE BASS VIOL is tuned in fifths C,G,D,A, one octave below the celloinstead of in fourths as done at present. This gives the bass a rangeeg ual to that of the other members of the violin family. A fifthstring, a C string, has been added in some cases, but this seemsnine ce ssary. "

The above quotation from Mr. llautrich does not exjjlicitiy say so,but the series of instruments was based on the principle that alldimensions should be in strict proportion to the tonal range of theinstrument. The violin -as we know it is the only instrument for whichdimensions are traditionally standardized, for example, a body lengthof 14 inches. The viola and cello are more variable, having beensubjected to a great deal more experimentation in an attempt to arrive

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GEOMETRICAL SQALIN& FACTORS

The outer pair of lines represents body length; the others,going inwards,, represent width of lower bout,, width, ofupper bout,, width of 0 bout,, and height of ribs.

at the optimum desired quality. The viola,, in particular,, has beenthe victim of such variability since in. addition to the matter of itsacoustical worth,, there has been the need for a compromise with easeof playing,, i.e. a smaller size. Mr. Dautrich as we have seenadopted the premise that the violin and cello (of. average size) arecorrectly proportioned. On this basis he constructed a diagram, whichwe have reproduced, relating dimensions and tonal range. Note how farout of line the conventional viola is for its range. This diagramshows by interpolation the dimensions which he actually used inconstructing the vilonia,.. vilon,, and vilono. We have also reproduced a

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drawing showing these instruments, together with the violin, violoncelloand bass viol. Clearly, the differences in proportions are more regular'than m trie usual series, shwn for comparison. The question of propergraduations for the tops and backs is one where we have no informationabout mr. Dautrich's methods. Presumably it was his skill as a violinmaker and his intuition which made these instruments as successful asthey turned out to be. Later acoustical research has shed considerablelight on the problems of plate graduations, and this topic will he coveredin a subsequent contribution to this history

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This story would not be complete without mention of the actual useoi these instruments. The "Fred L. Dautrich Quintet" gave a dozen or,iore performances beginning in 1933, including appearances at the JuillSchool of music, Carnegie Hall (before the National Orchestral Society) °and various music clubs in Connecticut. Reviews were invariablyfavorable, and it Js indeed unfortunate that limited funding and publicitycaused _ these instruments to disappear from the musical scene for"along time. Carleen H utchins in recent years acq uired a set of theseinstruments from the Dautrich estate and their reappearance will bedescribed in another issue., }. X

nis.°n

af Plea^re to present a photograph of the Quintet takenby Karl Gall about 1933 which shows Fred L. Dautrich (standing) andthe following performers:William Beach, violinHelene Halabe (Mrs. Jean L. Dautrich), viloniaRaymond Green, vilonoJean L Dautrich, celloWilliam Khoury, vilon

Thanks are due Douglas Ogawa for his cooperation, and his skillm making such excellent copies of this photograph from an oldyellowed print.

POSSIBLE EFFECTS OF SHEAR IN BRINGING VIOLIN PLATES TO OPTIMUMCONDITION — Carleen Hutchir.s

As a top or back plate is thinned to final dimensions and checked atintervals in the process by the tap tone test, it is possible to watchon the oscilloscope the changes in ho.th the amplitude and frequency ofthe main resonances. The closer the plate comes to the standards ofgood violin making practice (which I have learned from. F

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Sacconi andKarl Berger) the greater is the amplitude of the resonances and themore numerous. (Lottermoser at the German Bureau of Standards, who isworking with their violin industry, also reports this). This featureis particularly noticeable when shaping a bass bar after it is gluedinto the top plate. If one shaves off even a bit too much wood, thereappears a sharp drop in peak amplitudes. In other words, the conditionof optimum RING- or. response of each plate, so precious to violinmakers, can actually be checked on the asdlloscope as a plate isbrought to optimum dimensions. Eugen Skudrzyk (physicist,Perm* State)thinks that this phenomenon is directly related to shear factors in thewood. He, John Schelleng, and I plan further experimental studies inan attempt to understand this behavior.

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BACK AHL BELLY CLAMPS — Gordon. McDonaldmen I first got interested i*/^ny first jots was the makMJg; of a »*t o~ °3xlo J^oapa^ the mating£mtrihuted many good ideas* and others have f*g*W$ i££x

ßt,% whichand use of this type of .<*^P- * a* ***u^,Sf L tadwds of years,.aas occasioned this revie w of £c ideas in"J^^d Soots and%ven.the spool type clamp has beezLUSsa. jis -«««

Osa Mate a

e^^^SiSliuS! rS^atg»^^^»®SSn« mlgh^ he as

f0l"cIaiPs should M small,, light, *tUk «4 easy to apply

Jlt^e\-*r ?«J£f;>ji"J, ~.^rp^e^at^eoSerf^te5.o Should minimize chances oi breaking, ww auco

* ?SeS"fshoSfhe^ex^littl, open space between the pressure pads of

8 bolts or screws in contact with pi a*, eagws *""J

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vw hPttpro.btee.„ uuj.w uxfftrse stratus, but it^s probably better

Brass is not as 1lively to a^^*X~7^> \Yii mltaL screws and theto eliminate any possible contac-c be umen one ui^ao. so.

0 TrherHhous.d bo good accessibility for removing, excess glue.

i6. These clamps should lie easy to make.i -,--„> -^ -t-v. p

Q-fo.vre

is shown by*he proposed clamp to take c,.r* 0.. txe a,o ,c. -. q^i- ore©r.the sketches. Some comments on the **"*W^tf - and" a new type with

1 A rough check of a spool ©lamp with a ±tt -luuu ana a iuw

o i n ?4. a^rew. both viola rax aa, indicated. piu«.oa-.tJ uu u.^ <* w

|4^J 2i? pounds per >«>_» inch. Both had.wir,g. jnw*i* weretllhwS to what felt lilca a reasonable '« row Thelfsquare inch is <nun& to oauae permanent dexoxwat^on ..ft wxi ow„

are cr.de figure, hat fctdloato th^3,^^^K/dfscretion.t« bolts and that o«at« *£°"P^Tapproximate the average

2„The curva-roro 0: the clam^, pay- "^ f«

tte c , s £ad cornerscurvature of the upper and lower Ho.-.la. --ho.o -- "" , iffere£twill require a shorter radius of ajavato^ andJ^llesh^p curves atcurvatures might he need to adva^ta^e .«oawt o_ *-. «>«. _.

SafIti,o*ar!S to°soe toft oo^*« aouJ.d be «ed if pressure is not

applied toIS -Wb of the plat, out,ide oi *^ 1^i.HeoprettJ does not seem to to affec.ad by *-.o^ S"£» thean^ misplaced glue does » taau »**«, J^S. ;«?* Attached to

plate and is a nuisance to clear, up, "'--"- -«^ d1I 3tore for use

the wood by using cement available m anj au.o ~.ippi, - o

with auto door gasfcets, e-fco.

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cross-section

10-24 screwclearance to keep pressure off edge

sufficient width to accommodatecurvature of pads.

clearance hole #12 drill. Other end#28 drill and 10-24 tapA - 3/4 of thickness of edge ofplate -hthickness of neoprene

B -

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clearance -f- pad width -f- allowancefor pad curvature

lower bouts,about 2/3 oftotal numberof clamps.

X = overhang of plates over ribs

upper and vary degree oflower bouts. curvature of

pads, also widthof blocks. forblocks used atcorners, chiseloff excess woodoutside pads.

>BaiIkIHAKY STUDIES Otf VIOLIN &JJUi!ott PATTYS - Stewart Hegemani nd Garleen Hutchins

We have applied a loudspeaker technique to testing an instrumenttsing a wide band excitation and omnidirectional piokup. Exploratory;ests indicated that controlled procedures of this sort might gilzse■aluable information on instrument performance. Preliminary observationsshow that violins and violas which were properly balanced for plate;ap -uones were nearly omnidirectional in"radiation; while those known;o have improper tap tone relationships were nearly unidirectional,dth radiation coming primarily from their tops.

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RESPONSE OP A PLATE IK THE REGION, OP UNRESOLVED RESONANCES,AS AFFECTED BY DAMPINGr — Arthur H. Benade

Consider a violin plate as a two-dimensional wave carrying mediumwith defined boundary conditions. (These may be "free* or "fixed" oreven "mixed",, but without too many constraints that are applied awayfrom its bounding judges.) I£ this plate is excited at some point bymeans of a- rarrts^ie -fre quency constant-force driver., and if theamplitude response is observed at some other point by some sort ofdetector,, it. is possible to otitaiii- a frequency response which willshow peaks; and dips that are controlled by the nature of the reson-ances of th© system' and b# the positions of the driver and pickup.At low frequencies- only a few widely-spaced resonances are found,,whose properties have been, extensively studied as a means for guidingthe adjustment of violins. It is the intention of this note to callattention to the possibility of using; the statistical behavior of thehigher-frequency resonances as a way of obtaining ani overall impressionof the properties ofl' the wood used in. making the plate„ in particularthe frequency dependence of the damping; of the wood. There are twomotivations for proposing,- the method. First „ it can be used in a regionor frequency where 'conventional resonance methods of measurement aredifficult.; As a matter of fact it can work precisely because theresonances are poorly resolved 'at high frequencies,, but where it ispossible' £o make statistical" statements about the average response.Second,, it appears that usefuS qualitative information can be obtainedwhich does not depend much on the detailed shape of the plate, or (moreparticularly) oil the degree toward a set of proportions which are suitedto the actual piece of wood, under consideration.

At driving frequencies hig#i enough that the closely spaced resonance a(separated by an amount that is less tham the half-power band width g;of the individual resonances) are no longer resolved from one another,,we can write for the average response integrated over many resonances thefollowing simple formula:

Response « const, (l/d) 1 - (l/B).(g^j), ttd^p)Eere, o> is the driving, frequencyft & is the half-power bandwidth- of theresonances in the neighborhood ofa)„ and E(d,.p) is a. messy and uninter-esting, function, that depends om the particular positions of the driverand pickup. This function is irrelevant to our purposes because it merelycauses fluctuations above and below the much smoother wiggliness of thetrue response function, the average of this being; represented by theremaining; parts of the formula.

Let us now see what is the laboratory meaning; of this expression.A plot of the response measured in dedbels is expected to fall with,rising frequency at the rate of 6 dtr/octave iff the ratio {,&/<£) is constantIf. (gA>)< gsows with, frequency,, then the response curve will fall morerapidly than 6 d£/octave„ the converse is true if (g/id); falls with,frequency. The point of the analysis may be put rather briefly. We haveseparated out the "obvious" (1/io) part of the response. This part of: thevariation come 6 from the geometrical facts of life .pertaining, to anywaves whatever. The remaining factor contains the interesting physics:it is the departures from (1/ij) behavior which tell about the special

properties oi wood, in a manner which appears reasonably independent ofthe measurement technique and which requires only relative measurements.

N

Thil pace dearly iltuitratea tbe Improvement* ol the new

DAUTRICH

nystem over ihe

13

The sketch bel-ow will suggest the way in which experimental datacan be plotted for convenient study.

Wiggly line due to unresolvedresonances and the humpy

The presumption is that a smooth curve which is fitted to the upperfrequency end of the ol*served response curve will ,serve as the "signature"for a particular kind and condition of wood. This curve would presumablyre tain, its shape for any reasonable attempt at keeping the geometry thesame from sample to sample. This is in marked contrast to the rigorousprecautions- which must he. observed in the measurement off damping bymeans of isolated resonances. "

The possible musical application of this result arises ffrom the factthat we 'have a way to see how the damping; of a given sample varies withfrequency,, in a manner that is pretty much independent o£ other propertiesof the vibrating, system (wood,, driver,, pickup). If the general trend ofthe smoothed, line drawn through the higher-frequency part of the responsecurve for some particular component wood in a fiddle is characteristicallysteeper, less steep, or equally steep as a 6 db/octave line, then we havea possible way of quickly finding; out whether a new sample of wood iscomparable and useful for making; this component. All that is required isto out a slab, of roughly the same size and shape as the original sample,and plot the response curve. One does not, have to worry about the detailsof the bumps in the curve, nor about their positions. It is only theoverall trend that is important: is it or is it not of the same generalchar^cter^as that pf the original piece. It will of course take someexperiment: to see whetftei: the differences between different kinds ofwood ar# in fact sufficiently large for this test to be useful.

14

lICROSCOPIC EXAMINATION OF WOOD Ellis KellertSome time ago at a meeting, of several,research members of the Society,here was considerable discussion about the microscopy of the woods inId violins. Apparently little is known, on. the subject and it was felthat effort in this direction migfrt be fruitful. The writer agreed tonitiate an. investigation.It soon became apparent that although much had already been publishedn the microscopy of wood, all previous studies have been made on thin,

.icrotome sections. Such techniques invariably involve chemical treatment:lxatives,., solvents,, and dehydrating agents. Feeling strongly that treat-'tent of this sort may destroy some of the features of interest, I consid-red an approach -that would obviate the use of all chemicals. In this

.aimer it was hoped to reveal hitherto unknown cellular structures andntercellular objects such as crystals that'might affect vibrations inhe wood.This study began with the employment of thick cubes of wood the surfacesf which were highly polished,, cleaned and viewed in the microscope bycans of reflected light. It is quite surprising how clearly the cellsnd other structures appear with magnification of lOx to lOOx; particu-

ariy when a highly refractive liquid is placed on the surface underbservation. Preliminary studies indicated the practicality of the method,ittle new information has been derived as yet, but the study will beontinued and other light sources such as ultraviolet light and fluor-scent methods will be employed.

**'■'

URTHER STUDIES OF "MOISTURE BREATHING" BY WOOD — Robert FryxellIn Newsletter #2 (Nav„l964^ I discussed "moisture breathing" by wood,.nd the effect and possible consequences on a violin in terms of a shift.n the tap tone, and perhaps even a significant amount of adversede-tuning" of the top and back plates. John Schelleng, points out that;he total effect may be even more severe than these results indicatedsince the frequency measurements were only in. the with-grain direction-:ross-grain changes are known, to be considerably greater.Others have pointed out some additional consequences which may result"rom such weight changes^g^ example ,; the amplitude of a resonance peak

Lay be depressed and damping, may be increased if: the weight shifts eitheray from what it was when the plate was (properly) graduated. These two;henomena are collectively known to the violin maker as "ring" and he iscry aware how sensitive the proper "ring" is to graduations. In other■ords, it is reasonable to expect that a change in weight - by moisturereathing - is detrimental in the same sense as is poor graduations.

My previous report (subsequently published in THE STRAD,Feb. I96S inn enlarged version, copy enclosed) was based on studies of small rectang-lar bars of wood. Such a shape and size made it much easier to handlearge numbers of samples, and resonance frequency measurements also wereimpler and more reliable than with actual plates. I have since made acries of weight change measurements with 17/ actual plates, under con-i tions ranging from dry indooj* winter heat to 100$ relative humidityail at normal temperatures frSn 7..0-80 ft). The^gJ^gß.H. tests involveduspending the plates in a five gallon, sealed container which contained

. tray of water in the bottom. Periodically the plates were removedriefly for weighing. ■

15

The -results can be summarized as follows:1. For both maple and spruce in the white, the difference in weights was

as high as 8# between dry indoor heat (February) and 100# R.H. Moderately

humid August weather was in between, somewhat closer to the. 100^ R.H.condition. There was no significant difference between the two species

nor was there any relation to age which ranged from 4 to over 100 years.

2. Three coated plates were tested alohg with the above and showed onlyabout 3/4 the capacity fbr moisture "breathing as those in the white.rpVi q-fr ■ceorfi "(a) Carleen Hutchins spruce top, varnished 1948 hut no filler added.

(b) Carleen Hutchins maple back, linseed oil applied 1953 out not.varnished.

(c) Santus Serafin top* original varnish* early loth century.These three were strikingly consistent, and thus show, that agB in itselfhas not lessened the moisture breathing,.

3 There is a tremendous difference in the rates of' weights gain and weightloss* for both in the white and varnished plates. When taken from a verydry environment and placed, in the 100^ R.H. container* they showed verygradual weight gains and in fact were still changing slightly when theexposure was terminated after 1& weeks. On the other hand, removal fromthe container into ordinary room air (either dry winter heat or moderatesummer wither) resulted in extremely rapid weight losses. Within a perioderf say, 4to 10 hours,, the plates had arrived at the equilibrium weights

for their environment. It would be instructive to relate this large

difference in rates to the change in behavior of an instrument when movedfrom dry to htfmld surroundings and vice versa.4. A few of the plates were Viibla backri, in the white,, made from otherspecies of woods. Only one of each was available,, but tentatively itlooks like cherry and sycamore have a lower capacity than maple formoisture breathing;, and teak and paduc still less^

dm

OH. THE PHYSICAL EFFECTS OF VIOLIN VARNISH — John CU Schelleng

This is a work report on a project. which has not gone very far inspite of considerable effort, but which may be of some interest becauseof the one significant result which has been. obtained. The aim has been,and continues to be,, to measure the physical properties of varnish whichare important acoustically, and to correlate them with violin response.In his article published in the STRAD (mentioned above), R. E. Fryxellhas pointedly commented on the customary neglect of these considerationsas contrasted with the strong emphasis placed on visual beauty. What

most needs study is the questions Exactly what does varnishi do to a

violin acoustically? Aside from the indirect but important function ofpreservation of tone-, it is the elastic: and damping properties and the

mass with which we are most concerned (some of these may prove to benegligible , of course). Excessive elastic stiffness could conceivably

harm the instrument by altering the tuning of wood resonances, excessive

damping by smothering the vibrations. It is difficult to see how yar-nishirS can actually improve an instrument which has been optimallyadjusted in the white, and as far as I know, scientific opinion is unan-

imous in the belief that a good varnish is one that does no damage./imong violin makers also, the opinion is commonly expressed that a var-

nished instrument never sounds quite as well as it did in the white,though the idea of a direct improvement often intrudes.

The only measurements on varnish; that I have seen an the violinLiterature are those of Meinel (Jour. Acoust.Soc. Amer. ,vol. 29,r7„i9WJ "

16

He gives interesting curves showing a more or less linear increase ofdecrement with frequency, wood being the substrate. He found that a hardvarnish gives a smaller increase of loss with rising frequency than asoft one. Not sufficient data are given to calculate Rw (see (3) below),and no mention is made of frequency change .

The aim of my experiments has been to measure logarithmic decrementdamping) and Young's modulus and also mass. To that end a substrate

of glass has been used in the form of a strip about 16 x 1.5 x 0. 2 cm,supported non-rigidly at vibrational nodes and excited magnetically bya very small armature of soft iron glued at one end, the vibrationsbeing picked up acoustically by a microphone close to the strip. Glasshas been employed because of its mechanical stability, freedom fromhygroscopic effects, and freedom from a tendency to absorb varnish.It is probable however that in the future I shall return to spruce usingthe cross-grain orientation. Both substrates have their advantages, ofwhich more will be said later.Experimental result: The one measurement has used "Amber Oil Varnish"made hy E, Harris, "England, and kindly furnished by C. M. Hutchins.The conclusions are as follows.

loDamping produced by the varnish increased during the first severaldays after application. This increase was first noticeable at 5500 eps;the rise which occurred at 1100 eps put in its appearance a few days latei

2.Within the range from 400 to 5500 eps, the damping after a sixmonth drying period was substantially independent of frequency.

3.0 If R is the mechanical resistance of a cube of the varnish (in thesame condition as the film after six months drying), the imaginarycomponent of Young's modulus is Rw = 2,2 x 10^ dynes per cm 2.( w = 2nf x frequency).

4oThe real component of "Young's modulus was too small as comparedwith that of glass to produce a measureable change in frequency. Thiswill probably not be true when wood is used instead of glass.

soUsing5 o Using data of this sort,, it is possible to estimate roughly whatthe effect would be if the varnish were applied to a typical violin. Inan earlier memorandum I have estimated the losses in a violin in thewhite which result from (a) the internal friction in spruce and maple,and (b) radiation resistance. Using the same admittedly crude method,,we may now add the effect of this particular varnish, which was assumedto have a typical thickness of 0-.005". The result is a lowering of thepeaks of wood resonance by about two decibels. Averaged over valleysas v/ell as peaks 9. the loss might approximate one decibel. That this lossis not to be ignored is apparent when it is compared with the fivedecibels which separate un outstandingly full-tone* instrument from onewhich is on the verge of mediocrity (Lottermoser)., Use of an inferiorvarnish could easily spell mischief. And even with this reputedly goodvarnish, what will be the effect of long drying?

Obviously we need to investigate fillers also. The foregoing estimateassumes that a good filler isolates the varnish from the substrate.

It may be tjjfltt the "secret of the old Italian varnish" is rather asecret of varnishing. In the Hill book on Stradivarius, a similar remarkis made without venturing, to enlighten us further. Could it be that thesecret is the technique of using the least possible amount of varnish?This might include as sub-secrets a virtuosity in preparing a wood surfacewith the ultimate in smoothness, a varnish having a consistency whichis optimal for smooth application, and a brush or other tool which givesohe maximum effectiveness per mil of thickness,.

17

Further details: The following table summarizes the results of the

experiment.

Average: -1.3 .00286 .00155k K-l*

The first column gives the ordinal number of the "tone" The secondgivls frequency. Though the strip (old window glass) |*P^ed considerably5 \„a +~ the freauencies form a series close to theoretical.

fa^het%&e^Increments than my old strip. (The average Q,^^^ °ld glaSs was IXO0 'much of the loss may have been extraneous to the glass).

The third column gives frequency after varnishingJ^.f^' *f entfourth the frequency change (always a drop , while the fifth gives percent

SoH= tm» is constant within experimental error and is all

SfS! tfthfmass o? ?h?varnish. This is shown by weighing beforeand^af^ffremoval of the varnish the mass of thegrams and that of the varnish 0.33, a change of. 2. 4*..The average oi°nlllllm five representing a frequency decrease of 1.3*, is almost exactly

onStent with this 2.4* increase in mass. Since frequency dependsinversely on the squar4 root of mass, one would expect the change infreaufncy to he one-half the change of mass, that is, 1.2* provided there

ff^ntLr cause The 1.2* and 1.3* are so close together that it is not$olBSJ£w significant elastic effect in the varnish that

would he detected with experiments of this accuracy.

This absence of an elastic effect from varnish on glass does notmmiv a similar absence for varnish on wood. Comparing the modulus of

glased efx 1010 with a typical cross-grain modulus in spruce ofo q i lOlO'cgs, itis obvious that the modulus for varnish could easilyS; nLli«iblf with respect to that of glass while being considerable with

res^ft to that of wood! Glass is therefore unsuitable in measuring

elaftioity of varnish. For this purpose cross-grain spruce should be

acceptable, in spite of hygroscopicity. gone measurement of Young's modulus for varnish is at hand: 6 x 10

coSl°«w"«^!»SS»" nS. "a. S«. i. " thousandfold di«=oo„aa

i"e?vraS a rS measurement of the modulus of a rubber band gave

flTio67sale'o?der Is varnish measurement quoted). My dynamic measure-ment of thfimSSSr? modulus of varnish, Hw, is 400 times greater.

Tone. Fre queno; Decremenin c

12345

4131155227037535602

407/- 21140224237065531

-5.8-15---28.-47.-71.

-1.4-1.3-1.25-1.25-1.27

.00300

.0026. 00314--.00268.00288

.00454.00423.00481.00413.00434

.00154

.00163.00167.00145.00146

18

The varnSf .1 s lld° ,6 ' 7>and 8 «ive decrements as measuredthough

rthe

Shvi?esSare

Shr::gh^ X^Xt these*^■*I" toM t0 tone <by the process of subtraction which *aye the Litr;a,tlonß Ztre "eh reduced

""* £S S^Sfe^^"I-

*'l «I\\VSS°MnfL* ff±n r Perl^ental err- "hf^creLntof our interest. X varnxshlnS " independent of frequency within the range

formuLrIU6S °f HW °ited StoVe Utem 5) - obtained by the following

/

RwA6~ 3ir — A y

HeEs'/nere Es is modulus of substrate,y Staf thick2e ss of varnish (sum of both sides)Hs is thickness of substrate. 8J 'The same fonwla was used in estimating the effect of varnish on spruce

Again it is the editor's pleasure to thank .+h*many members whnqp wn-n+w i~Ti -vT'naaK: tne

niadP +hi« f w^ose worthy contributions havemaae this issue possible.

Robert E. Fryxell