04. Changing pitch
Materials
- plastic straw
- scissors
- patience
Method
Take a straw and flatten one end
Cut out a "v" shape in the flattened end of the straw
The cut end of the straw acts like the reed from a woodwind instrument. Place the "reed" of the straw on your lower lip, close mouth gently - not too tightly - over it, and blow steadily until it makes a sound. Don't let your teeth touch the straw. With your lips barely touching, blow steadily, gradually increasing your lip pressure.
Once you succeed in making a noise, try snipping the end off the straw while you are blowing. What happens to the pitch (highness or lowness) of the sound?
Try fitting another uncut straw into the end of your straw to make it longer. What happens to the pitch now?
Try cutting small holes along the top of the straw. cover all of the holes with your fingers and blow into it again. Now lift different fingers to open the holes one at a time. What happens to the pitch?
Can you...
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