Basics

• Project TitlePhysics of Music & Sound
• ThemeExploring the science of music and sound.
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• Submitted ByJennifer Leonard
• OrganizationThe Skills Library
• Brief DescriptionA series of projects that introduce the concepts of acoustic and electronic music and sound. Copper-pipe xylophones are a highlight, along with electronic circuits that explore the conversion of electrical current to sound and sound to current.
• Materials / ResourcesFOR XYLOPHONES:
  2 10-foot lengths of copper pipe for a low-pitched xylophone; or
  1 10-foot length of copper pipe for a higher-pitched xylophone
  Pipe cutting tool
  Metal 18 inch ruler
  String, foam or rope for base
  
  FOR OTHER MUSICAL INSTRUMENTS:
  Cereal boxes
  Rubber bands or elastic cord
  Paper towel tubes
  Wooden spoons or dowels
  Electronic guitar tuner
  
  ELECTRONIC KITS AS AVAILABLE
  We use SnapCircuits and Thames & Kosmos Electronic kits
  We also use the SnapCircuits "Snapino" version of Arduino., which works with any computer.
  
• Pre-requisite knowledge(If you include an electronic circuit, you need to be familiar with the electronics kit(s) that you are using. If you include an Arduino/Snapino circuit, you need to be familiar with that program.)

Units / Activities

• QuestionGive students a 1-page vocabulary/instructions sheet.
  
  ASK: What is a scientific definition of music? Encourage a variety of responses.
  
  
  
• DISCUSSIONDefine music as the arrangement of sounds with varying pitch, duration and tone, arranged to be pleasing to a listener.
  
  Define the concept of PITCH (high notes and low notes) and describe the math-science connection. The pitch of a note is based on the frequency of vibration, which is based on the length of a vibrating string or column of air. The mathematician Pythagoras helped to discovered there are certain ratios that produce sounds the blend together in a way that is pleasant. Other ratios clash.... think about how it sounds when you play two keys on the piano that are side-by-side. These ratios are universal worldwide. While different cultures use different musical scales, they are all based on the same frequency ratios.
  
• INTRODUCE THE PROJECTSExplain that there will be several project stations -- (1.) Xylphones; (2.) Make-your-own-musical-instrument from odds and ends; (3.) Electronic circuits that make music. In all of these, music is based on vibrations and different frequencies -- whether the variations in the length of a string or xylophone bar or variations in the current going through an electronic circuit.
• HANDS-ON PROJECTSSee activity sheets

Activity Sheets

• Xylophones

  Use pipe cutter to cut copper pipe to each length. 

  Use a piece of tape to label each as it is completed.  

  Lay the pipes on a strip of foam or rope.  Or tie with strng to create a hanging xylophone.  Try to set the point of contact about 1/5 the length from each end.  Adjust to make sure each pipe is centered and to make sure you get a clear sound from each.

   

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• Musical instruments from odds-and-ends

  Skills:

  • Experimenting
  • Building
  • Listening to sounds

  Knowledge:

  • Science and Engineering:
    • Sound is generated by vibration
    • Sounds vary by volume, pitch and tone
    • The engineering process is based on trying out variations on a basic design concept. (Varying the materials, size, and construction)

  Materials for cardboard box guitars:

  • Elastic cord (available in jewelry making supply section of art stores)
  • Rubber bands (purchase or save rubber bands that come on fresh vegetables)
  • Empty cardboard boxes - pasta, granola, crackers, etc. Dimensions can vary - ideally about 6" wide x 9" high x 2" deep. Some pasta boxes have windows already cut out, which is ideal.
  • Cardstock paper or other heavy-weight paper that can be folded
  • Tape
  • Kid-sized scissors (to cut elastic cord)
  • Adult-sized scissors or knife (an adult will cut holes in the cardboard boxes for sound holes)

  Materials for other instruments

  Shakers:

  • Plastic cups or cardboard tubes
  • tape
  • pasta, rice or dried beans

     

  Xylophones/flutes/sticks:

  • Thin metal or plastic tubes (size of a pen)
  • Wooden chopsticks 
  • Wooden dowels or wooden spoons

     

  Gongs:

  • Plastic or metal lids with holes pre-punched (for gongs)
  • (and a hole-punch for pre-punching holes)

     

  Drums:

  • Round cardboard oatmeal boxes or other round containers
  • paper
  • kid-sized scissors
  • tape

  "Washboards:"

  • Cardstock paper for folding (fan style)
  • Sticks for scraping against the washboard

  Preparation

  1. Make an example of a guitar
  2. Make examples of a few other instruments
  3. Pre-cut holes in the other cardboard boxes (or have a helper who can cut holes as the children work)
  4. Punch holes in some lids for gongs
  5. Put all the materials in a box (or a few boxes) so that children can choose materials for their projects.
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• Physics of Music & Sound

  Vibrations in the air are translated into SOUND by our ears.   Sounds can vary in: 

  • VOLUME (loud or soft) 
  • PITCH (high notes or low notes) 
  • DURATION (how long the sound continues) 
  • TIMBRE or VOICE (the quality of the sound, such as smooth or scratchy; very pure, or with lots of echoes or overtones).   

  Pitch … Do we hear a high note or low note or medium note?  Pitch is based on the frequency of the sound.... 

  Frequency … which is measured in Hertz (HZ) … which is a measure of the number of vibrations/cycles per second

  FREQUENCIES for a C Major Scale 

  C (low) = 262 vibrations per second
  D = 294;
  E = 330;
  F = 349;
  G = 392;
  A = 440;
  B = 494;
  C (high) = 523;

  Notice that the the frequency for high C is about twice the frequency for low C. 

  RATIOS -- the relationship of one number to another... such as a 12" string and a 6" string have a 2-to-1 ratio.     When we play a guitar or violin, we play different notes but changing the length of the vibrating part of the string.... there are certain lengths (and ratios) that sound "musical" to us. 

  Acoustic ... sound is produced by the vibration of physical objects such as strings or sheets of wood or metal or a column of air inside a pipe.  

  Electronic ... sound is produced by an electronic circuit, with the vibrations in the circuit translated into sounds we can hear through a speaker.  

• OPTIONAL / ARDUINO / SNAPINO SKETCH - LIGHT-Activated piano

  const int buttonPin=2;
  const int ledPin=10;
  const int ledPin2=9;
  const int speakerPin=11;
  const int C1=262;
  const int Dn=294;
  const int En=330;
  const int Fn=349;
  const int Gn=392;
  const int An=440;
  const int Bn=494;
  const int C2=523;

  
   
  int buttonState=0;
  int notefrequency=440;

  const int phototransistor = A0;
  int Val = 0;

  
  void setup(){
      Serial.begin(9600);
      pinMode(ledPin, OUTPUT);
      pinMode(ledPin2, OUTPUT);
      pinMode(buttonPin,INPUT);  
      pinMode(speakerPin, OUTPUT);
      pinMode(phototransistor,INPUT);     
  }

  
  void loop() {

  
    Val = analogRead(phototransistor); //
   
      Serial.println (Val);

      if (Val<200) {notefrequency=Val; }
      else if (Val<300) {notefrequency=C1; }
      else if (Val<400) {notefrequency=Dn; }
      else if (Val<500) {notefrequency=En; }
      else if (Val<600) {notefrequency=Fn; }  
      else if (Val<700) {notefrequency=Gn; }  
     else if (Val<800) {notefrequency=An; }  
     else if (Val<900) {notefrequency=Bn; }   
     else if (Val<1000) {notefrequency=C2; }   
      else {notefrequency=Val; }

   {
      tone(speakerPin, notefrequency);
       if (Val<500) {digitalWrite (ledPin, HIGH); }
       else { digitalWrite (ledPin2, HIGH); }
       delay(400);
      noTone(speakerPin);
        digitalWrite (ledPin, LOW); 
        digitalWrite (ledPin2, LOW);               
       delay(50); }
       }

• OPTIONAL / Arduino / Snapino Sketch -- Play a scale

  const int buttonPin=2;
  const int ledPin=13;
  const int speakerPin=11;
  int buttonState=0;

  const int C1=262;
  const int Dn=294;
  const int En=330;
  const int Fn=349;
  const int Gn=392;
  const int An=440;
  const int Bn=494;
  const int C2=523;

  const int phototransistor = A0;
  int Val = 0;

  void setup(){
      Serial.begin(9600);
      pinMode(ledPin, OUTPUT);
      pinMode(buttonPin,INPUT);  
      pinMode(speakerPin, OUTPUT);
      pinMode(phototransistor,INPUT);     
  }
  void loop() {

  
    Val = analogRead(phototransistor); //Read the value of the A2 pin and assign that value to Val

      if (Val<500) {
            Serial.println (Val);
    
      tone(speakerPin, C1);
      delay(250);
      noTone(speakerPin);
      delay(50); 
     
      tone(speakerPin, Dn);
      delay(250);
      noTone(speakerPin);
      delay(50); 
              
       tone(speakerPin, En);
      delay(250);
      noTone(speakerPin);
      delay(50);

      tone(speakerPin, Fn);
      delay(250);
      noTone(speakerPin);
      delay(50);

      tone(speakerPin, Gn);
      delay(250);
      noTone(speakerPin);
      delay(50); 
     
      tone(speakerPin, An);
      delay(250);
      noTone(speakerPin);
      delay(50); 
              
       tone(speakerPin, Bn);
      delay(250);
      noTone(speakerPin);
      delay(50);

      tone(speakerPin, C2);
      delay(550);
      noTone(speakerPin);
      delay(100);    

    }
    else
    {
      noTone(speakerPin);
      digitalWrite (ledPin, LOW);    
    }
  }

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Tags = science | physics/sound | electronics | Science-Wednesdays | Arduino/Snapino | Subject = Science | Grade Level = Elem, MS | Time Period = | Program/Funding = |

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Direct website link to this project: http://ContextualLearningPortal.org/contextual.asp?projectnumber=652.0016