key signature

American  

noun

Music.

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

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key signature British  

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

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Etymology

Origin of key signature

First recorded in 1870–75

Example Sentences

Others found fault with the way the U of R group measured the material’s magnetic behavior, a key signature of superconductivity.

From Science Magazine • Mar. 8, 2023

Chunky bracelets and earrings rounded out the looks, a key signature of the designer.

From Reuters • Sep. 27, 2022

Water is considered a key signature of life beyond Earth, after all.

From Salon • Jul. 13, 2022

Things like dynamics, key signature, time signature, and a song’s overall structure can be taken in by an experienced musician almost intuitively.

From The Verge • Nov. 18, 2020

So you can also say that the name of the key signature is a perfect fourth lower than the name of the final flat.

From "Understanding Basic Music Theory" by Catherine Schmidt-Jones and Russel Jones