Tubes and Tones

Put your ear close to one of the tubes. Listen to the tone and try to memorize it. Now listen to another tube. Compare the tones. Are they different?

2500 years ago, the Pythagoreans discovered that the pitch of a tone is related to the lengths of the tubes: the shorter the tube, the higher the tone. In particular, if you cut a tube in half, you will hear a tone which is an octave higher.