The toy piano, also known as the kinderklavier, is a small piano-like musical instrument. Most modern toy pianos use round metal rods, as opposed to strings in a regular piano, to produce sound. The U.S. Library of Congress recognizes the toy piano as a unique instrument with the subject designation, Toy Piano Scores: M175 T69. The most famous example of a dedicated composition for the instrument is the "Suite for Toy Piano" (1948) by John Cage.

The piano is a keyboard instrument that produces sound when its keys are depressed, through engagement of an action whose hammers strike strings. Most pianos have a row of 88 black and white keys, representing each note of the chromatic scale as they repeat throughout the keyboard's span of seven and a quarter octaves. There are 52 white keys, known as “naturals”, and 36 black keys, known as “sharps”. The naturals repeat a pattern of whole steps and half steps unique to any given starting note. These patterns define a diatonic scale. The 36 sharps repeat a pattern of whole steps and minor thirds, which defines a pentatonic scale.