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

For this choreographer, music means everything; his title is a wink, not to the work’s worth, but to its key signature.

From New York Times • Aug. 9, 2023

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

When sharps and flats are used, remember that the alteration is always from the scale of the chord root, not from the key signature.

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