Kazoo | A small, simple wind instrument made from a hollow pipe with a hole in it, over which is a thin covering that vibrates and produces a buzzing sound when the player sings or hums into the pipe.
Kettledrum | A large drum shaped like a bowl, with a membrane that is adjustable for tension (and, therefore, pitch) stretched across. (See also timpani.)
Key | A tonal center; the relationship between tones with a common center or tonic. Also a lever on a keyboard or woodwind instrument.
Keyboard | A set of levers (called ‘keys’) arranged in a chromatic scale on a piano or similar instrument.
Keynote | (See tonic.)
Kick drum | (See bass drum.)