Hi mbrock, Here are a couple of things to try to find out if it is the sax or the reed. The next time it happens, try playing on just the mouthpiece and neck to see if the tone and response returns. Another thing to try when it happens is to take an index card or a business card and carefully slip it between the the reed and the mouthpiece as far as it will go and keep it there several seconds. Oftentimes too much pressure from the top and bottom on a softer reed will cause it to warp and bend up toward the mouthpiece effectively closing the tip opening. The solution to this of course is to use a slightly stiffer reed, to push in more with the corners of the mouth and not bite so hard, and possibly take a bit more of the mouthpiece into the mouth. John