A keyboard instrument is a type of musical instrument that is played by pressing keys on a keyboard. HARPSICHORD, with 11 letters, is a stringed keyboard instrument that was popular in the Baroque period. PIANO, with 5 letters, is a popular keyboard instrument that produces sound when its keys are pressed. ORGAN, also with 5 letters, is a keyboard instrument that produces sound when air is pushed through pipes. Celesta, with 7 letters, is a keyboard instrument that produces a bell-like sound. SPINET, with 6 letters, is a small HARPSICHORD or clavichord. HARMONIUM, with 9 letters, is a keyboard instrument that produces sound when air is pumped through reeds. CLAVIER, with 7 letters, is a generic term for any keyboard instrument. Moog, with 4 letters, is an electronic keyboard instrument. CELESTE, with 7 letters, is a keyboard instrument that produces a bell-like sound. CALLIOPE, with 8 letters, is a keyboard instrument that produces sound when steam is pushed through whistles. Typewriter, with 10 letters, is an early keyboard instrument that produces sound when keys are pressed. Americanorgan, with 13 letters, is a type of ORGAN that produces sound when air is pushed through pipes.