Are you thinking about submitting a jazz performance? If so, do you know any jazz standards? Seeing that you’re a horn player, maybe a Charlie Parker or John Contrane tune, like Confirmation, Anthropology, Au Privave. Are any of the adults in the jazz band professionals or semi-professional musicians? I’d ask the rhythm section (piano, bass, drums) to see if they’d be willing to record a few tunes. Rehearse a bit and get a decent video recorder. Keep the recordings pretty short, like the melody and one or two choruses (3-4 minutes). If you poke around some of the music schools’ jazz audition requirements, you’ll see that they almost all ask for a blues, a rhythm changes and maybe a ballad.
For practicing, there are “play-along” tracks for just about any standard available on youtube and the like. If you can’t get a live rhythm section together, I think many schools would accept you playing along with a play-along track for the supplement submission. (Oberlin actually requires using their play-along tracks for jazz prescreens.)