How do instruments make different sounds?

Instruments sound different because each one vibrates air in its own way. Pitch comes from how fast something vibrates, while the instrument's shape, material, and starting motion change the mix of extra tones. That mix gives a violin, drum, or flute its sound color.

A plucked string begins with a crisp burst, a bowed string can keep singing, and a drum skin fades after a hit. Hollow bodies, bells, reeds, and stretched skins all boost some vibrations and quiet others. Your ear hears that pattern as a familiar instrument.