The third most common clef is a type of C-clef, and it’s the mainstay of viola players across the land: the alto clef (some people just call it ‘viola clef’ for this reason).
The alto clef is primarily used for the viola, a mid-ranged instrument, while the tenor clef is sometimes employed in cello, bassoon, and trombone music (although the principal clef used for these instruments is the bass clef).
The three clef symbols used in modern music notation are the G-clef, F-clef, and C-clef. Placing these clefs on a line fixes a reference note to that line—an F-clef fixes the F below middle C, a C-clef fixes middle C, and a G-clef fixes the G above middle C.
A clef is a symbol that specifies the pitch of the notes in the staff. The most common clefs are the treble clef and the bass clef. Learn more about clefs.
A musical-notation symbol at the beginning of a music staff, a clef indicates the pitch of the notes on the staff. Clefs were originally letters, identifying letter-named pitches, that were added to one or more of the staff's lines (thus providing a "key" to their identity).
The bass clef is also called an F clef because it wraps around the highest F note (F3–the F below middle C) on the bass staff. It’s usually the second clef that musicians learn after treble, as it is placed on the bottom staff in the grand staff for piano.
Clef, in musical notation, symbol placed at the beginning of the staff, determining the pitch of a particular line and thus setting a reference for, or giving a “key” to, all notes of the staff.