Organ composition reached a great peak in the work of J.S.Bach, but then people started to lose interest. Not many developments took place in organ-building during the Classical music period. Although Mozart played the organ and called it the “King of Instruments” he did not often write music for it. Among the organ builders at this time were Joseph and Claude-Ignace Callinet who built the organ at Notre-Dame's (St. Etienne, Loire) in 1837.