A kettledrum is a large percussion instrument that looks like a giant copper or brass bowl with a tight sheet of material (called a drumhead) stretched across the top. When a musician strikes the drumhead with special mallets, the drum produces a deep, resonant boom that can rumble through an entire concert hall.

Kettledrums are also called timpani (tim-pah-nee), their Italian name, and they're the only drums in an orchestra that can be tuned to specific musical notes. A foot pedal lets the player tighten or loosen the drumhead during a performance, changing the pitch instantly. Most orchestras use several kettledrums of different sizes to create different notes.

You might recognize the powerful kettledrum sound from dramatic movie soundtracks or classical pieces like Beethoven's symphonies, where they can build tension or announce something important.

Unlike smaller drums that provide steady rhythm, kettledrums tend to play specific notes at crucial moments: a thundering roll during a storm scene, a triumphant boom in a victory, or ominous rumbles when something dangerous approaches. When you hear that earth-shaking boom in an orchestra, that's probably the kettledrums making their presence known.