I haven't listened to them for a while, but the French rock duo Air have produced some really good songs. Their tracks have a unique style, some of them feature an introspective, ethereal mood (The Virgin Suicides OST is my favorite of their albums). So it should be no surprise that they have nongames on their website too! To play them, go to their official website and, from the main menu, choose "Play". There, you will be able select from nine short nongames (plus Pong).