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Transcript of multifónicos oboe
Multiphonics for the Oboe Nora Post
Reproduced from INTERFACE by arrangement with the editors.
ABSTRACT This paper explores four aspects of multiphonic sounds as they pertain to the oboe definition, acoustical properties, notation, and compositional usage. The article provides a detailed multiphonic fingering chart as well as a brief discussion of (1) the notation of oboe fingering generally and the multiphonic fingering chart in particular; (2) slurred multiphonics; and (3) the factors which affect the reliability of oboe multiphonics.
DEFINITION AND NOTATION The impact of multiphonics on today's repertoire is undisputed. Of all the recent expanded techniques for the woodwinds, the interest in, and development of, multiphonics has been far more extensive than that of any other "new" sound. This development has been advantageous for the oboe, which possesses an extraordinary ability to execute a great variety of multiphonic sounds. The oboe can make an almost imperceptible pianissimo multiphonic entrance - and it can produce an immediately incisive fortissimo attack. Well-chosen multiphonics can be articulated at the same speeds as the most rapid single sounds, including double and triple tonguing. More than anything else, it is this responsiveness which accounts for the reliability - and consequent attractiveness - of oboe multiphonics. There are several types of multiphonics for the oboe. But first, a working definition is essential. What, exactly, is a multiphonic? Bruno Bartolozzi (1967, p. 35) offers one explanation: "... the generation, at one and the same time, of a number of frequency vibrations in the single air column of an instrument." Or, as Arthur Benade (1976, p. 565) describes it: A multiphonic oscillation is made up of a collection of components whose frequencies are connected to one another by an elaborate set of heterodyne relationships. The ordinary tones of woodwind instruments also fit this description, but the frequency components in normal tones are limited to those belonging to a single harmonic series. As to the process involved: "These chords result from fingering patterns which in principle provide several tube- lengths on which to provide composite tones." (Read, 1976, p. 150). Does singing and playing simultaneously constitute a multiphonic? Technically speaking, singing/playing and multiphonics are both the same acoustic phenomena, although they are produced by different means. On some wind instruments - the flute
2 and saxophone, for example - singing and playing sometimes cannot be distinguished from multiphonics.  (This is not the case with the oboe, due primarily to its limited capacity for singing and playing.) But, while singing and playing is the result of one tone being played and one being sung, multiphonics are produced exclusively by the vibrating system of the instrument. Since singing and playing do not satisfy this criterion, they will be excluded from my comments. There is considerable diversity about the manner in which multiphonics are notated. From the performer's viewpoint, any notational system is acceptable if it efficiently conveys accurate information. This is no easy task. Bartolozzi sought clarity via numbers representing the keys of the woodwind instruments (Fig. 1). His system had a substantial influence upon composers during the years immediately following the publication of his book. Of late, this influence has waned. Performers find his notation awkward because it requires that arbitrary numbers representing each key of an instrument be memorized. It is quite natural for an oboist to see "B" written in a fingering; it is time consuming to see "9" written in a score, forcing the performer to consult Bartolozzi's book to decipher the composer's intention and then to translate Bartolozzi's notation into standard fingering symbols. It is unfortunate that a number of outstanding composers employed a system which creates unnecessary difficulties for the performer. I have devised what is, in my opinion, a simpler and clearer notation for multiphonic, as well as other, fingerings. It entails depicting the six main tone holes of the oboe, including a dividing line between right and left hands, and then giving letter names for all other keys. Fig. 2 indicates two fingerings of the same multiphonic - the left utilizing
the Bartolozzi system, the right using mine. Aside from variants of the two systems of multiphonic notation described above, other multiphonic notation deals with indeterminate or only partly-determined multiphonics. David Cope  employs the sign to indicate indeterminate multiphonics. Vinko Globokar, on the other hand, utilizes several different multiphonic notations, depending upon the context. Most often, however, he uses the symbol "M" above a note, and places under it either a number specifying how many pitches should be in the multiphonic or alternatively, provides pitchless noteheads representing the total number of tones desired. (Fig. 3)
3 There are two groups of multiphonic sounds for the oboe. The first is what Bartolozzi calls "homogeneous chords". These are "...all sounds of approximately the same volume and colour..." (Bartolozzi, 1967, p. 42). The second group, which he calls "broken sounds", he describes as: ...chords containing sounds of different tone colour are obtained by emitting simultaneously two sounds which are close together, with their relative harmonics. In this way it is possible to exploit the phenomenon of "beats" caused by the interference in sound vibrations occurring when two sounds are emitted which are very close together, within the maximum space of a semitone. There are substantial differences between the sound and production of "beating" and normal oboe multiphonics. For that reason, beating multiphonics will be treated as a special subset. COMPOSITIONAL USAGE The uses of multiphonics are almost as numerous as they are diverse. The examples discussed below illustrate the vast variety of available multiphonic possibilities. Lucas Foss and Peter Schat have each written works which utilize oboe multiphonics for virtually their entire duration. The oboe part for Schat's Clockwise and AntiClockwise,  written in circular form, consists of twelve groups of multiphonics for three oboes. Beginning at any point, the players proceed either clockwise or counterclockwise, changing multiphonics at the conductor's signal. The effect is a homogeneous wash against which the rest of the piece is set. While the oboe part includes a catalogue of fingerings and pitches, the actual "boxes" of multiphonics show only fingerings (Ex. 1). Foss's The Cave of the Winds,  uses multiphonics, borrowed in toto from Bartolozzi, for all four woodwinds. Included in the score are Bartolozzi's drawings of the four instruments with his numbering of the keys. An unusual version of multiphonics has been the "orchestration" of their pitches - that is, having certain pitches doubled by other instruments in the ensemble. Ursula Mamlok  employs this device to reinforce the individual pitches of several sustained multiphonics in her Concerto for Oboe and Orchestra. In similar fashion, Paul Zonn  requires each of the other instruments to enter separately on one of the pitches of a sustained oboe multiphonic. Multiphonic ostinati patterns occur occasionally. Peter Salemi calls for numerous ostinati in his Riff 70/71, each of which is played at one of three recurrent speeds. Paul Earls demands something more difficult - the English Horn begins a slow, soft ostinato between several multiphonics; each time the pattern is repeated it must crescendo and accelerate. Furthermore, a new multiphonic must be added at each repetition. When all the indicated multiphonics have been added, the ostinato ends. Multiphonics are frequently employed in conjunction with other sounds, conventional or otherwise. A simple combination is the arrival at, and/or departure from, a multiphonic via one of its pitches. Although often encountered in the repertoire, this is possible only with certain multiphonics (see Remarks on Multiphonic Fingering Chart). However, one cannot always precisely predict when these multiphonics will sound.
4 Composers usually allow some time, consequently, for the embouchure to achieve the desired effect. Ton de Kruyf takes this into account when he adds F5 to the C6 (Ex. 2).
In contrast to most multiphonics, which speak tutti, there are some whose pitches can be phased in one by one (see Beating Multiphonic Fingering Chart). Occasionally, fluttertongue is added to a multiphonic. The result depends on the multiphonic chosen, for the denser multiphonics (i.e., those comprised of many pitches) are so complex that the added effect of fluttertongue is negligible. Two of the more successful examples of this technique are found in Toru Takemitsu, who adds singing to a fluttertongued multiphonic and then deletes fluttertongue from a multiphonic (Exs. 3 and 4). Multiphonics can sometimes be slurred together , although this demands a thorough knowledge of the oboe's fingering system. Iannis Xenakis does it quite expertly in the example given below (Ex. 5).  Composers often do not grasp the difference between a multiphonic trill and a multiphonic tremolo. A trilled multiphonic is one in which all the pitches of the multiphonic move in the same direction by a semitone. If the pitches do not change in this symmetrical fashion, what we have is, technically speaking, a tremolo. Consequently, many multiphonics marked "tr" are not actually trills, but tremolos. While most multiphonic trills and tremolos are executed the same way - i.e., only one finger moves - this does not necessarily produce a symmetrical semitone trill of all the pitches in the multiphonic. Takemitsu clearly distinguishes between trills and tremolo added to multiphonics (Ex. 6). In most case