On a standard piano with 88 keys, how many are black?

The piano is an acoustic, stringed musical instrument invented in Italy by Bartolomeo Cristofori around the year 1700 (the exact year is uncertain), in which the strings are struck by hammers. It is played using a keyboard, which is a row of keys (small levers) that the performer presses down or strikes with the fingers and thumbs of both hands to cause the hammers to strike the strings.

Most modern pianos have a row of 88 black and white keys, 52 white keys for the notes of the C major scale (C, D, E, F, G, A and B) and 36 shorter black keys, which are raised above the white keys, and set further back on the keyboard. This means that the piano can play 88 different pitches (or "notes"), going from the deepest bass range to the highest treble. The black keys are for the "accidentals" (F♯/G♭, G♯/A♭, A♯/B♭, C♯/D♭, and D♯/E♭), which are needed to play in all twelve keys. More rarely, some pianos have additional keys (which require additional strings). Most notes have three strings, except for the bass that graduates from one to two. The strings are sounded when keys are pressed or struck, and silenced by dampers when the hands are lifted from the keyboard.