Pitch

Rosalyn Winston                Walt Disney Magnet
                               4140 N. Marine Drive 
                               Chicago IL 60613
                               (312) 534-5840

Objectives:

1.  To use the phenomenological approach to problem-solving.
2.  To demonstrate the Scientific Process of Inquiry.
3.  To observe that the pitch of a sound varies by the length of the vibrating 
    medium.
4.  To make a musical instrument by varying the length of the vibrating soda
    straws.
 
Materials:

Apparatus needed for a class: overhead projector, overhead projector pens, 
transparencies, metric rulers, pens, pencils, scissors, tape, 8  21" soda straws
per student, open pipe or donated carpet end tubes cut to specified lengths, 
African Musical Instruments from the Field Museum, tape recorder, instrumental 
musical tape, computer banner, poster of President Clinton playing the 
saxophone.

Strategy:

 1. Saw open pipes or carpet end tubes to the exact specification in The Physics
    Teacher, May 1986, p.313. (1.32, 1.20, 1.04, .99, .88, .78, .70, .66 meters)         
 2. Use the open pipes for the phenomenological introduction to pitch. 
    Place the carpet end tubes on a table from tallest to smallest.
    The teacher picks up each tube and listens in silence. (Background noise is 
    very useful here.)
    Ask for student volunteers to come up and listen to each pipe.
    Ask the students what did they hear.
    Ask the students what did they observe about the tubes.
    Ask the students what changed as a result of the difference in the length of 
    the carpet end tubes.
 3. Make a web of their answers on the board or paper.
 4. Make up a hypothesis from the web of observations.
    For example, does the length of the carpet end tube determine the pitch of
    the sound it produces?
 5. Test the hypothesis by making Straw Pan Pipes to these exact specifications:
    #1. 21.4 cm, #2. 19.0 cm, #3. 17.1 cm, #4. 16.1 cm, #5. 14.3 cm, #6. 12.8cm, 
    #7. 11.4 cm, #8. 10.7 cm
 6. Let students work in cooperative learning teams making the Straw Pan Pipes.
 7. Allow the students time to practice playing a specific song together.
 8. Have all cooperative learning teams play the selected song together. 
 9. Ask students to write a paragraph telling what they learned from this  
    experience.  While they are writing play an instrumental tape. 
10. Have another teacher bring in the poster of President Clinton.
11. Indicate Mr. Clinton came to see what they have learned about pitch.
12. Ask for student volunteers to read their compositions.

Performance Assessment:

    Use a xylophone the next day and ask what do you observe about the pitch.
    Ask them to take their Straw Pan Pipes home and practice playing a specific
    song for class the next day.