The term 'kind of clef' refers to the three main types of clefs used in musical notation. The BASS clef is a symbol that indicates the pitch of notes on a staff, and is also known as the F clef because it wraps around the line representing the note F. The TREBLE clef is a symbol that indicates the pitch of notes on a staff, and is also known as the G clef because it wraps around the line representing the note G. The ALTO clef is a symbol that indicates the pitch of notes on a staff, and is also known as the C clef because it wraps around the line representing the note C. All three clefs are used to indicate the range of notes that can be played on a particular instrument.