Johann Sebastian Bach's chorale preludes are varied and artistic not only in the treatment of chorale melodies, but also in the accompaniments of those chorale melodies. This study examines the accompaniments of Bach's long chorale preludes, focusing on identifying the various types and the characteristics that make them unique. This study investigates the two broad categories of accompaniments depending on whether the motives are chorale-derived or independent of the chorale. While the chorale prelude accompaniments in the first large group are closely related, the accompaniments of the chorale preludes in the second group stand independently and illustrate the vast range of Bach's compositional skill. Both groups demonstrate Bach's interest in expanding his predecessors' models, a trait that can be traced throughout all of Bach's compositional history.