The adventures of Beethoven Bear and Mozart Mouse continue in this series of supplementary books written to correlate with the Music for Little Mozarts series. In Halloween Fun! Book 1, Beethoven Bear and Mozart Mouse go to the pumpkin patch to find the perfect pumpkin. In Halloween Fun! Book 2, Clara Schumann-Cat helps Beethoven Bear, Mozart Mouse, and J. S. Bunny create perfect Halloween costumes. In Halloween Fun! Book 3, Mozart Mouse and Beethoven Bear teach Professor Haydn Hippo how to trick-or-treat for his first time. In Halloween Fun! Book 4, the Music Friends receive a special surprise invitation to a Halloween party.