1.1 Sound and music activities  (Page 5/5)

Procedure

1. Have the students hang the objects securely from the dowel.
2. The students should then strike the objects one at a time, listening carefully to the sound each object typically makes.

Discussion questions

• Does the size of the object seem to affect its pitch/frequency? Its loudness?
• Does the shape of the object seem to affect its pitch/frequency? Its loudness?
• Does the object's material seem to affect its pitch/frequency? Its loudness?
• Can you tell what effects the thickness of an object has on its sound?
• What seems to affect how long a sound lasts?
• What objects make the sounds that you like best? Which do you think would make good percussion instruments? Why?
• Which of these effects do you think you can explain in terms of waves and the vibrations the objects must be making?

Instrument body activities

Objectives and assessment

• Objectives - The student will construct a simple megaphone, and will use the megaphone and a music box in several simple investigations to explore the effects that the body of an instrument has on its sound.
• Evaluation - Assess student learning using worksheets or answers to discussion questions.

Materials and preparation

• Decide whether each step of this investigation will be a teacher demonstration or an individual or small-group activity.
• You will need a music box.
• You will need several large, flat surfaces of different types of materials - different types of wood and metal as well as plastic and softer surfaces will be particularly instructive. A box or drawer made of hardwood is optional.
• You will also need large sheets of paper, construction paper, newspaper, soft, pliable plastic or foam or poster board, and some tape, OR a megaphone. If you have a variety of megaphone materials, have different students use different materials to see if material choice affects the sound.
• For older or more independent students, you may want to make copies of the discussion questions.

Procedure

1. Wind the music box and let everyone listen to it while holding it in your hand.
2. Place the box on different surfaces and listen to the difference it makes in the sound. Continue to wind it as necessary to hear a long example of each surface. If you can, place the music box inside a wooden box or drawer.
3. If you do not have a real megaphone to demonstrate, let the students make their own megaphones by rolling the paper into a cone shape, open at both ends. Tape it if necessary to hold the shape.
4. Let them talk or sing into their megaphones and otherwise experiment with how the megaphone changes sounds. Experiment with different megaphone sizes and shapes (narrow or widely flaring).

Discussion questions

• What effect does each surface have on the sound from the music box? What is causing these effects? (Answer: some surfaces will vibrate with the music box if they are touching. See Resonance .)
• Why do instruments have bodies; why aren't they just a bunch of strings or a reed or a membrane to beat on?
• Why would an instrument maker choose to make an instrument body out of wood (like a violin or piano)? Why might metal be chosen (as in brass and many percussion instruments)? Of the other materials you experimented with, would you make instruments out of them? What kind of instrument with each material? Why?
• How does a megaphone shape change a sound? Does it matter whether the megaphone is narrow or flaring?
• How do you think the megaphones would have changed if they had been made of wood or of metal?
• Would a violin sound louder if you were sitting right in front of it or next to it? What about a trumpet? What's the difference?
• Based on your observations, what do you think the shape of the instrument does to the sound of a tuba, trumpet, trombone, clarinet, or saxophone? What about flutes and bassoons (which do not flare)?