Here's a schedule of when each show has its slots. Auditions take place between 6 pm and midnight all five days. If you're trying out, you mig ht want to show up a little before a slot begins, to increase your chances of an early audition.
Auditions are for one show at a time.
If you are interested in a specific show, come to Common Casting when that show has a slot and sign your name on that show's audition list. A show's list is only available for sign-up during that show's audition slots. Actors are strongly encouraged to fill out one sheet early on and then make as many xeroxes of it as necessary. The other exception is that, for auditions for the American Repertory Theatre, actors need to prepare two one-minute monologues, one contemporary and one classical. You also do not need to be familiar with the shows you audition for, although it may help when reading scenes for the directors.