Radical Reed experiment

Name: ________________________________ Date: ___________


All sound, including that of reed instrument are caused by vibrations. Your voice is caused by your vocal cords vibrating. Vocal cords are like a musical instrument that uses reeds: thin strips of wood that vibrate when you blow over them. A clarinet is an example of such an instrument.


1 plastic straw



1. Squish or bite one end of the straw flat.

2. Cut the flat end into a point as shown.

3. Put the cut end in your mouth far enough so that you can put your lips around the round part of the straw.

4. Now blow hard. Can you make a sound?

5. While you are making a sound, gently touch the cut end of straw with your tongue. What can you feel?



6. Now cut a small hole half way down in the top of your clarinet.

7. Cover the hole with your finger and blow into the clarinet.

8. While you are blowing, lift your finger to open the hole. What happens?




The pitch of the flute is determined by how much air is inside the clarinet. When you cut a hole it's the same as if you had cut off the straw. The shorter straw has less air inside and so has a higher pitch.

Last Update: May 5, 1996

Copyright 1996, D.M.Candelora. All rights reserved.Reproduction for educational use is encouragedas long as this copyright notice is included.