So my parents finally bought me an alto last March (I had 3 years under my belt then) and it's a student yamaha. I thought it sounded fine, and I played fairly decent with it. Marching band passed, and no problems. I got a new mouthpiece (Selmer c star) before auditioning for an all east TN honor band a few months ago in December (I made it), and I thought I sounded good still. My teacher said my sound was fine. Recently, for the past month or two, I've been noticing a subtle "buzzy" sound when I play, and at first I thought it was the reed. I changed reeds and found out that was not the case. I showed my band director, and he said it shouldn't be a problem. I showed my teacher, too, but he said he couldn't hear it. I even gave my friend a chance to play my sax, and we both could hear it. Fast track to a few days ago; I got my sax out to start practicing, and immediately I was hit with the very noticeable buzzy sound... but much worse than before. Almost every note has the buzzy sound in it; especially middle g through middle d. I'm going to meet my teacher about it in a few days. But, would anyone know any reason for this just suddenly happening? I feel like it could be my mouthpiece, since it has tiny scratches here and there, or my alto itself, or both. Any advice would be appreciated.