Yes, participants test/audition for class/ensemble placement at the beginning of the session (and can also choose to audition for various select ensembles if of interest or if recruited to audition). Rising seniors can also audition for undergrad scholarships a couple of weeks into the session (as I recall; I remember it being earlier than expected, anyway). Scholarships are announced at the blow-out concert (yes, parents may attend; some final performances are live-streamed as well).