Breathe. No. Really.

Sometimes when we really concentrate we forget to breathe. That sometimes happens when we have a hard exposed passage - either in a solo piece or chamber music. Breathing actually helps. Not breathing really doesn't. Try holding your breath and see if you are more or less tense. Tense mind, tense body, tense arms, tense hands, tense fingers....it's a slippery slope that breathing can help avoid.