Keyboard instruments sometimes get lumped into either the string family or the percussion family, but they’re really a hybrid of the two. When a player presses the key on the keyboard, it activates a hammer or a plectrum inside the instrument that either strikes (a hammer) or plucks (a plectrum) the strings. In the case of the organ, the keyboard opens the organ’s pipes and allows air to flow through them, producing sound.
All of these instruments can play many notes simultaneously, and they often fill out the texture or support other instruments in an ensemble.
Ludwig van Beethoven, Piano Sonata No 32, Op. 111 I. Maestoso–Allegro con brio ed appassionato (1822), performed by Daniel Barenboim
Frederic-Francois Chopin, Valse Brillante in E-flat Major, Op. 18 (1833) — performed by Lang Lang
Johann Sebastian Bach, Brandenburg Concerto No. 5 in D Major, BWV 1050, III. Allegro (excerpt) — performed by Gustav Leonhardt
Domenico Scarlatti (1685-1757), Sonata in D minor, K.517, performed by Elaine Comparone
György Ligeti, Continuum (1968), performed by John Hansmann McKean
Johann Sebastian Bach, Toccata and Fugue in D minor, BWV 565, performed by Hans-Andre Stamm
Frédéric-François Chopin, Etude Op. 10 No. 12 “Revolutionary” (1831), performed by Cameron Carpenter