Well is this for college scholarship? For the music program or is it just for a normal academic program? Usually students play Bach Prelude and Fugues for the boroque side of things. Sinfonia 15 will be fine, but some colleges specifically ask for a Bach P&F so it may be more time efficient to just learn a P&F. I would probably pick one out of book 2. I don't know what level you play at, but with the repertoire you mentioned, for classical era, maybe check out Beethoven's fifth sonata last movement. I think the Schubert will be fine. Maybe check out the Rachmaninoff Moment Musicaux as well. The faster ones really are much easier than they look. For contemporary, maybe check out Prokofiev Suggestion Diabolique.
I’m auditioning for a scholarship soon and need to know what pieces. I’ll need one from each period and it cannot go over 15 minutes (but try to keep it under ten). I’m thinking of Bach’s 15th Sinfonia for the baroque period. It’s around the level I’m at now and would like similar level pieces (harder, but not toooo much, is okay but definitely couldn’t be easier). I was also thinking maybe Schubert’s Moment Musicaux Op 94 No 3. for romantic but I’m not really set so please give me whatever suggestions you have.