First of all, do mouthpieces really affect your sound enough to justify paying a lot for a so called *good* one? If so then I`m thinking of getting the Selmer CP 100 mouthpiece. HAs anyone tried this one? Opinions on Selmer mouthpieces in general? Right now I`m using the one that came with my Selmer CL200 clarinet and with a Vandoren 3 1/2 reed and Rovner lig. I`ve been playing for a while and thought perhaps I should upgrade to something as little better. Thanks for any help! I will greatly appreciate it!

yes they do! almost more important than the clarinet itself. I recommend a vandoren mouthpiece. Although some people scoff at my opinion, but you should try them for yourself and see how you like them.