A clef is a musical symbol placed at the beginning of a staff to indicate the pitch of the notes on the staff. “Clef” is the French word for “key”. Clefs first started appearing in music scores in the late 1500’s as letters placed precisely on a specific staff line to identify letter-named pitches, which provided a “key” to their identity.
In modern music, there are three main clef designs / shapes we use for pitched music, plus some ancillary clefs used for percussion instruments, tablature and so forth.
