Playing or learning by ear is the ability of a performing musician to reproduce a piece of music they have heard, without having seen it notated in any form of sheet music. It is considered to be a desirable skill among musical performers, especially for those that play in a musical tradition where notating music is not the norm.

It is a misconception that musicians who play by ear do not have or do not require musical education, or have no theoretical understanding of the music they are playing.

Playing by ear is often also used to refer more generally to making music without using musical notation, perhaps using (elements of) improvisation and instant composition.

Blues, pop, jazz, and many forms of non-western music are fundamentally rooted in the concept of playing by ear, where musical compositions are passed down from generation to generation. In this respect, playing by ear can also be seen as a music-specific example of oral tradition.

The concept of playing by ear has led to the development of the idiom to play by ear or "play it by ear."