Pluck the rubber band over the open end of the cup. Describe what you see and hear when you pluck it hard or soft. The teacher fills pop bottles with water, tuning them to the first five notes of the scale. Students are asked to work with a partner to discover the differences in appearance and sound when the bottles are struck. Students should explain which bottles have the lowest pitch and try to arrange the bottles in an order of either ascending or descending pitch.
Students can explain how each instrument produces sound.
B. Students can discover what sound waves look like on an oscilloscope or other device. Have students draw pictures of resultant waves when various sound sources are used. Discuss frequency, amplitude and timbre and how the sound wave change for each of the various sounds. Also, refer to the web site, The Soundry, for more information about sound and on line experiments. The instruments should be made out of available materials at home or at school.