The percussion clef is a staff with a single line in the middle, and two dots placed above and below the line. The dots indicate that the notes should be played one octave higher or lower than written. The line indicates the middle pitch of the staff, which is C4.
The percussion clef is used for a wide variety of non-pitched percussion instruments, including claves, bongos, congas, and tambourines. It can also be used for pitched percussion instruments, such as vibraphones and marimbas, when they are playing non-pitched parts.
The percussion clef is a relatively recent development in musical notation. It was first used in the early 20th century by composers such as Igor Stravinsky and Edgard Varèse. Today, the percussion clef is used extensively in contemporary classical music, jazz, and popular music.