AR Resonance Glenn Van Looy Euphonium MouthpieceThe New Glenn Van Looy Signature Mouthpiece gives even more depth in sound and blends in with ensemble playing as well as solo performances. The ease of playing and clarity is remarkable thanks to a new design in the lower section of the cup. Also, now both the top and the backbore are in Phosophor Bronze, a material much harder to machine that allows for a much faster response, a broader and more resonant sound and a particularly crisp articulation.