<p>I am surprised at the length required by Princeton. </p>
<p>Our daughter had plenty of music to send (she is a composer), but called the admissions office (another Ivy) and subsequently, out of consideration, accompanied her CD with a note indicating which 3 minutes constituted her best work, so that they would not have to spend too much time on her supplement.</p>
<p>I have no idea whether admissions listened to her CD, or music faculty, or really whether anyone listened to her CD. (She also sent a resume and a couple of programs from concerts where her compositions had been performed, and, perhaps most importantly, two recommendations from teachers.)</p>
<p>That said, I have no doubt at all that her arts supplement helped her get in.</p>
<p>I would call the admissions dept. at Princeton or wherever and talk to them. Find out how long they would like your CD to be, and what they would consider appropriate for your instrument. You can also include, as I mentioned, a resume, programs, awards, and recommendations from teachers and others familiar with your work.</p>