Clef

[klef] or [klɛf]

(noun.) a musical notation written on a staff indicating the pitch of the notes following it.

Edited by Ben--From WordNet

(n.) A character used in musical notation to determine the position and pitch of the scale as represented on the staff.

Typed by Corinne

n. a musical character placed on the staff by which the absolute pitch of the notes is fixed.

Typed by Barack