This Reference 54 based on the Old Mark VI with high F# key.The sound is incredible! Very efficient to blow and incredible projection. It can take all the air anyone can put into it and the sound stays full, rich, and dark. In playing it side by side with the Series III, the differences are incredible. The III has a quick response, very centered, focused sound. The Reference is more like a turbo charged Ferrari – step on the pedal and it rockets. The Reference alto has all the flexibility to bend and shape notes and plays dead on in tune. Classical players may still prefer the Series III. It does have a nice dark sound but it will take more control (than the Series III) to fit the legit style. Many will want to own both saxophones for different jobs. A Series III for legit and pit orchestras and a Reference 54 for lead in a big band. Available in two finishes Vintage matte and dark lacquer.