a set of kettledrums vibrating = they're in use
Usually a set of 4.
Most orchestras will use a snare drum, a bass drum, and a set of timpanis.
The skin vibrates when you hit them.
The string of a veena vibrates
The reed on a clarinet vibrates against the mouthpiece.
There is no such thing as vibrates or non-vibrates. Vibration is a concept when dealing with sound waves. However, one may mean vertibrates and invertibrates. Vertibrates are those that have backbones and invertibrates do not.
The tightly stretched surface (membrane) of a drum vibrates.
The reed vibrates.
Violins, trumpets, piano, clarinets, cornets, harp, voice, cellos, lutes, timpanis, violas, flutes, recorders, etc.....
It's the string that vibrates when you either pluck or bow them.
The strings.
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