# Key signature

Source: https://arcosounds.com/glossary/key-signature

**A key signature is the group of sharps or flats written at the start of each staff line, indicating which notes are consistently altered throughout the piece.**

Sharps always appear in the order F, C, G, D, A, E, B and flats in the reverse order, B, E, A, D, G, C, F. Two shortcuts identify a major key at sight: for sharps, the key is a half step above the last sharp; for flats, the key is the second-to-last flat. Each major key signature is shared with its relative minor, a minor third below.

For a string player the key signature is more than a reading instruction, it determines the hand frame. D major on the violin sets a particular arrangement of high and low second fingers that stays consistent through the piece, so recognising the key means the hand is prepared before the first note.

Canonical source: https://arcosounds.com/glossary/key-signature