Choose one track and cue it for the best three minutes, or call and ask how much they want on the recording. That’s great that you have that letter of recommendation.
Did you decide against a music school?
One reason I think competitions and even early successes in the arts can sometimes be problematic, is that they do give an impression of being “the best.” Attention is sometimes lavished on precocious young people. Things can change once you are a freshman- not saying they will- but as jazzpianodad said and Casals indicated, you have a lifetime of growth as a musician ahead of you. Enjoy and good luck!