The J.A. Custom Discovery 48 Master has excellent response and tone. Upgraded with a new 2 part slide system the Discovery is one of the best 12 hole chromatic harmonicas on the market. Out-of-the-box chromatics are well known to have response issues on hole 10, 11, and 12, but on the Master model all holes and reeds are fully playable with equal response. The 2 part slide mechanism, gives the harmonica a much better slide action, but it also give the player better response and dynamics. The valves are modified for a much smoother action. It is assembled with screws for easy maintenance. Are you looking for a harmonica with incredible volume, perfect response and a smooth slide action, then you do not have to look any further!