Sound comes from vibrations

Put your fingers gently on your throat and hum. Feel the buzzing? Sound starts with something vibrating.

Sound is a form of energy. Pluck a stretched rubber band: it makes a sound only while it vibrates. When the vibration stops, the sound stops. No vibration, no sound.

A vibration is a quick, repeated back-and-forth movement (an oscillation). Many things can vibrate:

• strings (a sitar, a guitar);
• stretched skins (a drum, a tabla);
• columns of air: when you blow into a bansuri, the air inside the pipe vibrates.

The thing that makes a sound is its source. Most musical instruments have more than one vibrating part.

How we speak. In your voice box (the larynx) are two stretched flaps of muscle, the vocal cords. Air from your lungs makes them vibrate. Your tongue, lips, mouth and nose then shape that sound into words or music. Many animals use vocal cords too. Grasshoppers and crickets are different: they rub their wings or legs together.

Proof with a tuning fork. A tuning fork is a U-shaped metal bar (steel or aluminium) with a handle; its two arms are called prongs. Strike it on a rubber pad and it rings. You can't see it shaking, but touch a prong to water and it makes ripples: it is vibrating.

A village that sings names. In Kongthong, near Shillong in Meghalaya, known as the Whistling Village, every person has a "tune name" that can be sung or whistled. A mother makes up a lullaby-like tune for her baby at birth. The tradition is called *Jingrwai Iawbei*.