Musical StringsA 2nd Grade Science Lesson

Will BostwickCadee Ellis

Christen Hornbaker

Standards

California State Science Content Standards: Physical Science 1.g. Students know sound is made by vibrating objects and can be described by its pitch and volume.

Investigation/Experimentation Standards:a. Make predictions based on observed patterns and not on random guessing.g. Follow oral instructions for a scientific investigation.

Lesson Objectives

Students will be able to demonstrate understanding that pitch of a string is affected by diameter and tension.

Students will create a graph to show the relationship between pitch and tension

Students will predict change in pitch of strings in hypothetical situations based on previous observations and data.

Science Content

• The effect of frequency of sound on the ears is referred to as pitch

• The higher the frequency, the higher the pitch• Pitch is different than volume• Something can have a low pitch and a high volume• The pitch of a string is determined bu its length, tension, and

diameter

Essential Questions

1.What is the effect of diameter and tension on pitch?2.What is the difference between volume and pitch?

Assessment

Pre Assessment: Students will receive a piece of paper with a drawing of a neck of a guitar. The neck of the guitar has six strings on it. Students will label the guitar strings from highest pitch to lowest pitch. They will use a number scale and label the lowest pitch starting with number one and the highest pitch will be number six. The students will be asked to explain why they chose number six as the highest pitched and number one as the lowest pitched.Formative Assessment: Progress monitoring assessments will be made to provide real-time data informing the teacher of student progress towards learning goals. Progress monitoring will occur in both the Exploration and Concept Introduction phases of the learning cycle. Progress monitoring will occur in the Exploration phase with the teacher listening to ideas and misconceptions regarding the concept of pitch. Progress monitoring will continue in the Concept Introduction phase with the teacher’s assessing the graphs of each student pair. Progress monitoring will be used to ensure student understanding of learning goals and guide instructional adaptation as needed. A final formative assessment will be made after the Concept Introduction phase is complete with the teacher assessing the interactive vocal responses of each student.

Summative Assessment: A summative assessment will be made in the Concept Application phase of the Learning Cycle. Students will demonstrate understanding of the lesson concepts by ordering given strings from lowest pitch to highest pitch while making a cereal box guitar. Cereal box guitars will be graded by the teacher to assess final understanding and to note which students need re-teaching of the lesson concepts.

Engagement

The teacher will give every student a worksheet with a drawing of a guitar.  The teacher will ask the students to work independently and label the 6 strings based on pitch with the lowest pitched string numbered 1 and the highest pitched string numbered 6.  After they label their strings the students will explain why they numbered them the way that they did.  They will also explain what they think pitch is.  During this the teacher will listen without input to assess each students’ background knowledge as well as take notes on each students’ level of understanding.  

Exploration

For the exploration the students will work in heterogeneous pairs.  Each pair will be given two rubber bands of different diameters.  They will begin by predicting how to make noise with their rubber band and how they can manipulate the rubber band to create different pitches.  After a couple minutes of prediction they will be given rulers and a data sheet with two graphs and prompting questions.  Each graph will have pitch on one axis and tension or tightness on the other.  They will be exploring what they can do to the rubber band to get the pitch to change.  The students will complete one of the graphs for each of their rubber bands based on how the pitch changed when they stretched the rubber band to specific lengths.  While exploring the students will be focused on the questions: How does the pitch change as the rubber band is stretched?  Does the pitch of both rubber bands change in the same way when stretched?  and Do both rubber bands sound the same when stretched to the same distance?

Concept Introduction

Each group will have one person that will report the group’s results.  Each group will explain what they discovered during the exploration as well as what they noticed about the pitch of the rubber bands.  During these presentations the teacher will complete formative assessments to record what each group discovered during the exploration.  The students will discuss how the pitch changed when the rubber bands were stretched as well if they noticed any difference in the sound of the two rubber bands.  After the presentations the teacher will begin the powerpoint on pitch.  The teacher will explain how pitch is how high or low a sound is.  The teacher will also explain how pitch is different than volume.  The teacher will use either recordings or real instruments to demonstrate this concept.  The powerpoint will also demonstrate how pitch can be affected by tension, diameter, and length.

Science Concepts

Sound• Sound is a form of energy produced by the vibration of matter.  • Can be transmitted through gases, liquids, and solids.  • Travels faster and further through solids and liquids than it does

through gases.  • The distance and speed that the sound vibrations can travel is

determined by the elasticity and density of the object through which it is traveling.  

• Sound can travel 330 meters per second through air, while it can travel 1450 meters per second through water and 4800 meters per second through steel.

Science Concepts

Volume• Volume also refers to the loudness of sound • Volume is measured in decibels. • Factors that affect volume include: 

o Energyo Distanceo Surface Areao Resonance (an object vibrating at its natural speed)o Composition

• By changing any of these 5 factors, you can change the volume of the sound by forcing more vibrations.

Science Concepts

Frequency or Pitch• Frequency measures the number of vibrations per second.• Frequency is different than volume  • Frequency can be high or low. • Factors that affect pitch include: 

o Lengtho Tensiono Diameter

Science Concepts

Connection to the LessonThese 3 factors can all affect pitch and can be observed in this lesson by using a rubber band, but the affects can overlap and contradict each other so that it can be difficult to tell which factor is affecting the pitch.  By stretching a rubber band it will increase the length which will decrease pitch, but it will also decrease the tension and diameter which will both increase the pitch.  The overall affect is that stretching the rubber band will increase the pitch, but all 3 factors worked together to determine the pitch that we hear.

Science Concepts

Music• A musical tone is any sound produced by vibrations of matter. .  • Music has melody which refers to the tune, rhythm which refers to the

timing and harmony which refers to the pleasing sound of two or more notes played together.  

• Musical instruments fall into three major categories:  o String instruments (such as what we are demonstrating in this lesson)

produce sound by the vibration of stings through either plucking or bowing the strings.  

o Percussion instruments produce sounds by being struck.  o Wind instruments produce sound with vibrating air columns.  

• All instruments follow the principles discussed before to produce pitch and volume through sound.

Concept Application

The students will be given the materials necessary to complete the concept application.  Each student will receive a cereal box and 4 rubber bands with different diameters.  The teacher will explain the basics of how to assemble a cereal box guitar to get the students started.  The students will then assemble their guitars.  When they attach the strings the students will have to use their knowledge of pitch to put the strings on from lowest pitch on the left to highest pitch on the right.  When the students are through the teacher will assess their guitars to see if they were able to use their knowledge of pitch to correctly order the strings.

Differentiation for English Learners

• Each ELL will be paired up with a buddy to complete the activities so they can have some extra support if needed with vocabulary, comprehension of activity, or mastery of concept.

• There will be a word wall with all of the new vocabulary that students can refer to if there is a misunderstanding or misconception regarding the new vocab terms.

• Each ELL will receive a diagram with multiple pictures on it helping to explain what certain terms mean. The pictures will be of rubber bands that are stretched and at rest to show tight and loose. There will be arrows to show high and low that will be represent by an up arrow or a down arrow for pitch. There will be a thick and thin drawing of a rubber band to show different diameters as well.

• The graph that ELL students fill out will also have pictures/symbols on it to help with comprehension.

Differentiation for Students with Special Needs• Teacher will provide a hard copy of the powerpoint to John prior to the

presentation to help him follow along and pick out the main details• John will have a partner, who is strong in science, to work with during the

exploration phase to help John understand the content• The teacher will provide John with additional instruction if necessary to

clarify any misunderstandings• Roger will be provided with rubber bands that he will be able to

manipulate• Roger will have a partner who can assist him with physical aspects of the

lesson that he will struggle with

Differentiation for GATE Students

• Teacher will ask Melissa to explain her reasoning, in writing, for ordering the strings the way she did in the preassessment task, focusing on predictions and prior knowledge of string pitch dynamics.

• During exploration, Melissa will be asked to not only notice how the pitch of her rubber band changes with tension but will be asked to compare the pitch of her rubber band to the pitch of her partner’s rubber band. Melissa will be asked to make predictions about why the two rubber bands make different pitches when stretched to the same length (diameter).

• During the summative assessment, Melissa will be asked to give a verbal response explaining all of the factors determining the pitch of a string on a musical instrument. Melissa will be prompted to think about different string instruments she knows and will be asked to explain why they make either a high-pitched sound or a low-pitched sound.

Applications to Everyday Life

 

Websites

PBS Kids science experiments page. Includes many fun sound experiments!http://pbskids.org/zoom/activities/sci/

Another website with some fun sound experiment ideas. Also includes a few games/interactives for soundhttp://www.sciencekids.co.nz/sound.html

Link page to many different sites dealing with sound. Most links go to BBC kids pages. http://science.pppst.com/sound.html

Children's Literature

All About Sound by Lisa Trumbauer, Children’s Press, ISBN 0-516-23609-1, 2004

Sound (Science Works!) by Steve Parker, Gareth Stevens Publishing, ISBN 0-8368-1965-9, 1997

Resources

Friedl, A. E., & Koontz, T. Y. (2005).  Teaching science to children: An inquiry approach.NY: McGraw-Hill.