The term 'Violist Clef' is a musical notation that is used to indicate the pitch of notes on a staff. It is also known as an ALTO clef, which is indicated by the letter 'C' in four letters. This clef is used primarily by violists and other string instruments in the ALTO range. It is also used by some wind instruments, such as the oboe and English horn. The Violist Clef is used to indicate the middle range of notes, which is higher than the treble clef but lower than the bass clef.