The C clef is a musical symbol used to indicate the pitch of notes on a staff. It designates the position of the note C on the staff, which can vary depending on its placement. The most common forms of the C clef are the alto clef and the tenor clef, which are used primarily for instruments like the viola and trombone. When the C clef is placed on the second line of the staff, it represents the note C4, also known as middle C. This helps musicians read music more easily, as it provides a reference point for other notes. The C clef is essential for various musical compositions and arrangements.