key signature

noun

Music.

1. (in notation) the group of sharps or flats placed after the clef to indicate the tonality of the music following.

key signature

noun

1. music a group of sharps or flats appearing at the beginning of each stave line to indicate the key in which a piece, section, etc, is to be performed

Word History and Origins

Origin of key signature¹

First recorded in 1870–75