My self imposed limit is 3 pints before the gig, but I'll usually stick to just 1 or 2. It's good for relaxation - in one of the bands I'm in, our pre gig tipple is often a beer to relax, followed by a red bull chaser to get pumped up. I depped in a concert band once where the Tuba player managed 8 pints between the afternoon rehearsal and the evening gig (averaged out at approx 1 pint per half hour!). He was doing a solo in the concert. He almost fell over a couple of times as he walked out to the front. We were all pretty worried, but he played absolutely flawlessly. I have noticed that brass players seem to put more away before a gig than wind or strings...
My old clarinet teacher at University told me I needed to loosen up more when I played, and suggested I drink a bit before my next lesson. I only had half an hour between my lecture and the early afternoon clarinet lesson, but managed, with some encouragement, to get through 2 pints and 2 double scotches at the student bar. I went into the lesson and she told me I stank of booze - I had to remind her of her instructions, she'd forgotten she'd suggested it. Can't remember if she thought it made me player any better, but I do remember having a nice nap afterwards.
