The term 'Bass and Treble' refers to two musical clefs, which are symbols used in musical notation to indicate the pitch of written notes. The bass clef is also known as the F clef, as it wraps around the line representing the note F on the staff. The treble clef is also known as the G clef, as it wraps around the line representing the note G on the staff. Together, the bass and treble clefs are used to represent the full range of musical notes.