What is "play by ear"

vb. 1 (context transitive and intransitive of music English) To play guided by one's memory of the sound, rather than from a written score. 2 (context transitive and intransitive idiomatic English) To do by guessing, intuition, or trial and error; to react to events as they occur.

Play by ear may refer to:

• Improvisation, the act of inventing all or part of a process as it is performed.
• Learning music by ear, learning how to play a musical piece purely by listening to a rendition of the piece alone, without the aid of printed material