The term 'treble symbol' is used to refer to a CLEF, which is a musical symbol used to indicate the pitch of written notes. A CLEF is typically represented by a stylized letter and is placed at the beginning of a staff in written music. The two most common clefs are the G-CLEF and the C-CLEF. The G-CLEF is also known as the treble CLEF, and is represented by a stylized letter 'G' that encircles the second line of the staff. The C-CLEF is also known as the alto CLEF, and is represented by a stylized letter 'C' that is placed on the third line of the staff.