One-of-a-king 1928 vintage C.G. Conn 6M prototype alto sax, serial number 218413. This horn is a very early example of 6M experiments going on at the Conn factory. Some aspects are very much 6M-like, others are more like the other transitional models in this category, and some aspects are different from either. It is the earliest example of same-side bell keys we have every seen from Conn, and predates the other 'transitional' models by over 2 years. On display in the Saxquest Museum in St. Louis, MO.