The book contains piano accompaniments, but for extra sophistication a CD of backing tracks is also included. Each piece within the collection has two different backing tracks: the first (full performance) includes the backing track along with the instrumental melody; the second (backing only) presents the backing track alone. The full performance track is provided to help the player to the learn the melody and its interaction with the accompaniment; the melody is played on a marimba to avoid dominating the acoustic Â'liveÂ' instrument for those players who choose to play along with this version of the backing.