I have a 1916 Conn and prefer the tenor sound. I play tenor mainly, so I have a lot of tenor mouthpieces that I've tried on the C melody. While more of them than not sound terrible on it, for some reason the Runyons all sound great including current Custom, --clear and bright, 50's custom --darker and buzzier, old SR with serial number--dark and mellow with a little buzz, 22--similar, and quantum, which even w/o the spoiler screams out r&r. All of these are full sounding and subtone easily. How they would play on the Martin, however, I don't know.