This is not really directed at anyone in particular, due to topic age...But if you are going...
I hated school and church auditions, they were so stuffy, contrived, and needlessly tense. And my advice would not make you fail, only because I would remove the option by advising to just drop out and well, don't do that. You are capable, I am presuming, as they will. Just remember, regardless of whom or how many are gathered to evaluate you, every single one of them, no matter how thickly padded their resume with successes, there's at least a 50-50 chance they felt like you and also could have failed even more miserably than you are even possible of doing when you audition. Also remember, the feedback isn't designed for television ratings, it is directed to you for consideration and (hopefully) encouragement, not to slice you down to size. So using the contents I listed above for final advice; avoid the stuffiness by being glad and grateful for the opportunity, as Jane said; and the best way to diffuse any hint of facing a truly contrived set of expectations (especially on the difficulty or artistically limiting parameters scales) is to engage in brief conversation with a presumption of decent queries about anything being acceptable, it can almost force everyone to relax; and the more smiles (and laughs, if appropriate) you can release in earnest are going to be even more relaxing, and probably soften the edges to smooth. Finally, do not overreact or under-react to criticisms or accolades bestowed on you. 
Good LUCK!
You'll go through this again, many times, so...Good LUCK!!! 
Rock ON & Keep the Faith,
Rocket
edit: "just drop out" above should read better as don't bother enrolling, meant as not a disrespect, but I was thinking of those who have done the same sorts of things in their lives and gone on to tremendous accomplishments, as in anything is possible. Nothing against Berklee either...
"He still doesn't charge for mistakes!
"
http://jbonamassa.com/tour-dates/"Everybody wants ta get inta the act!"
“Now, this isn’t your ordinary party crowd, here. I mean, there are professionals in here.”
