Knight,
You’re already received lot’s of great advice, but there’s one specific concept that I didn’t see anyone target yet. Let’s say you do everything in all of the above posts (less the medication) and you find that you still move past that positive nervous energy to something that’s harmful to your playing. What then?
Your mind always wants to be busy. It needs something to occupy it. If you think to yourself “I’m not going to be nervous at my audition” you haven’t given your mind anything constructive to think about. It’s like telling a 4-year-old NOT to hit their brother. All they hear is “Hit Your Brother”!
I took an audition a couple of years ago that was one of my personal best showings. I really feel like I played as well as I was capable of playing (my nervous energy remained in check). My instructor gave me a concept that was a variation on something that Norm Bolter (2nd trombone in the BSO) said once. When he would go on stage to audition, he says a mantra to himself, "Pitch and Rhythm, Pitch and Rhythm". My instructor thought it would be better for me to flood my mind with what it is that is coming up (pure musical ideas) rather than "what ifs" and/or verbal commands. So I started to sing through the opening phrase of the Hummel (the first thing that I was to play in the auditon) to give my mind something constructive to do. It really worked for me!
Your conscious mind is literally like a little kid in audition situations, getting into mischief that will cause the rest of your body to perform below it’s capabilities. If you want your kids to be good in a busy waiting room and the associated appointment, you better bring some quiet activities along to keep them occupied until it’s your turn to accomplish your business. If you forget to plan the quiet activities, you are potentially going to be frustrated at them for being “kids”. You’ll spend your energy trying to keep them quiet and then you’ll be less prepared for your important meeting because your mind is less focused (just like the audition situation). Giving your conscious mind something to do (singing through musical phrases in your mind) is just like providing the quiet activity for your kids in the waiting room. It requires some preparation and discipline to do it, but the payoff is you can play to the level of your current preparation.
Keep simple (positive) music thoughts going through your head and your mind will allow you to play your best.
Here's a link to an article by
Bryan Edgett that you might enjoy.
Hope this helps!