What Is Sound? How Music Makes the Air Wiggle

Put your hand gently on your throat and hum a song: mmmmm. Feel that? A little buzz! That buzz is a sound being MADE. Every sound — a drum, a giggle, a beep, a song — starts with something wiggling back and forth super fast. That fast wiggling is called a vibration, and it is the secret behind all music.

In this lesson you will: • Learn that sound comes from things that vibrate (wiggle fast). • Find out how a wiggle travels through the air to your ears. • Tell the difference between a high sound and a low sound. • Make your own sound and change it.

When you pluck a rubber band, you can SEE it shake back and forth. That shaking is a vibration. While it wiggles, you hear a sound. When you stop it with your finger, the wiggle stops — and so does the sound! A guitar string does the same thing. So does the skin on a drum. Even your voice: little flaps in your throat wiggle to make you talk and sing.

When something wiggles, it pushes the air around it. That push bumps the next bit of air, and the next, all the way to your ears — like a line of dominoes falling. Inside your ear, the wiggling air tickles a tiny drum called your eardrum. Your eardrum wiggles too, and your brain says, "Aha — I hear a sound!"

Some sounds are HIGH, like a tiny bird or a squeaky mouse. Some sounds are LOW, like a big drum or a lion's roar. Here is the secret: fast wiggles make high sounds, and slow wiggles make low sounds. A tight, thin rubber band wiggles fast and squeaks high. A loose, fat one wiggles slow and sounds low. Music makers use this to play many notes!