I see a lot of today's rock/rap groups have a DJ. Linkin Park, Incubus, Limp Bizkit, and Sugar Ray come to mind. I can barely hear their tracks they're laying with all the sound coming from the guitars and drums. Occasionally, I hear a few record scratches. When I seem them perform on TV, I can see them spinning some records, but I can't tell if it's contributing to the music. Are these guys really playing music or just window dressing?