Windows/Mac: Freeware application MarioPaint Composer is a remake of the old-school Mario Paint game for the Super NES, but this one runs on your desktop. More specifically, it mimics the music generator feature of Mario Paint, which creates loops on a musical bar with different sounds tied to classic Nintendo icons. The download page claims that it's available for Windows and Mac, though when I followed the Mac link it just downloaded the Windows version, so your mileage may vary. MarioPaint Composer is freeware, Windows and (maybe) Mac only. If you don't have any composition chops, it's still worth a download just to listen to the familiar classic that's loaded by default.