A clef (from French: clef “key”) is a musical symbol used to indicate the pitch of written notes. Placed on one of the lines at the beginning of the stave, it indicates the name and pitch of the notes on that line. This line serves as a reference point by which the names of the notes on any other line or space of the stave may be determined. Only one clef that references a note in a space rather than on a line has ever been used. There are three types of clef used in modern music notation: F, C, and G. Each type of clef assigns a different reference note to the line (and in rare cases, the space...