I returned from a weeks holiday 3 weeks ago, I have been practicing daily since I returned, but I am having real trouble getting my lip back in for my upper register. I have been practicing lots of buzzing and long low notes but my lip seems to stop buzzing after an top A. My range before was a comfortable top C, but if I hit the note now my lip just stops buzzing. I am not sure what to work on to try to get this back. Could anybody help me with what I can do? I really need to sort this out as I am getting a little worried about it.