<p>Look over the requirements for these composition programs. It varies a lot. Some may just require the sheet music, whereas others may require CD samples/recordings. Some may not require any of this. You may wish to lean toward composition programs that only require your sheet music or no portfolio. As far as recordings, this may be tricky as you say you wrote pieces for choral, band and string quartet and so I am not sure if this is possible, but can you record the piano part (I assume you play)? Or piano with vocals for the choral pieces (perhaps with a few friends who sing the different parts)? Can you get four musicians at school together to record your string quartet pieces?</p>