I just started playing URB in my schools wind ensemble (just to annoy the orchestra teacher ) Anyways, I was reading about thumb position on URB. From what I gather, it's kind of like first positon, only you use your thumb on the fingerboard. (good way to injure yourself on EB) I've been getting along fine wihout using my thumb like that. What's the point? Where can I learn more about this? Thanks!