Hi, there! This is not the right place to post your question, but I'll give you the answer anyway.
If you think of mp3, wav, midi... there is NO way to put any executable code in that type of files (same for pictures).
Still, maybe you can write a program that will play your mp3 for a few days. You can store you mp3 in the exe file, so they don't have the actual mp3.
Note: That's only one of the ideas. The other is to give them samples of your music (20 seconds, example).