An interchangeable 6-tune cylinder for a Mermod Frères music box. The pins for all 6 tunes are interleaved so that nudging the cylinder along its axis selects the next tune.

St. Croix was a center of fine watchmaking and the Mermod family had been watchmakers there since the late 18th century. Swiss watchmakers were the first to make music box mechanisms in the early 18th century.