The supplementary books Duets with an Open String Part are available for violin viola & cello. The duet books provide additional folk & traditional tunes with simple open string parts. The supplementary books Duets with an Open String Part are available for violin viola & cello. The duet books provide additional folk & traditional tunes with simple open string parts. The tunes may be sung or played by the teacher a family member or a more advanced student on strings piano or other instrument. The duet book can be used alongside Book One of the series to develop confident rhythm & bowing skills. Beginners make satisfying music right from the start!