Just thinking back on all the variations of the audition experience for VP. If they ask you to choose your first piece, go with your BEST piece because you may not get to sing a second one. Often, D was stopped in the middle of her second piece. It was rare for her to sing all three she had prepared as part of the required package. This is not necessarily a reflection on your skill - it just means they heard enough to know what’s what. Some schools have piano skills assessment and theory tests in addition to auditions. I will summarize what I remember for particular schools in the 2016 season.
EASTMAN had a one on one interview with the admissions representative as well a group presentation, theory, aural skills, and piano tests.
VANDERBILT had a huge dinner at Maggianos for all the kids and parents who auditioned and an admissions person was at each table. They administered a theory test and had a sample lesson with the voice chair as part of the audition.
U MARYLAND had a group presentation with piano skills and theory tests.
NORTHWESTERN/BIENEN had a group presentation by all voice faculty with several undergrads singing. There was a small wine and cheese reception at the end of the audition day. Honestly, I can’t recall if they did theory and aural skills or not.
RICE had a theory/aural skills test and they provided class schedules up front in order to attend sample classes, but otherwise it was very perfunctory, in and out. Same for DE PAUL (this was prior to the new music building’s completion). Can’t remember SMU - we spent considerable time there taking sample lessons but I don’t recall what was organized as part or the interview itself.
Good luck to all!!