Instruct: Classify an Amazon review as either positive or negative.
Query: Heavy, yet interesting music

System of a Down is a great band. I hadn't heard their music until I saw the "Sugar" video on MTV. After that, I had to buy the disc. I absolutely love it. My favorite song is probably "CUBErt," but they're all very good. As some reviewers have already said, Serj's voice is difficult to get used to, but I think his timbre (if you can call it that) is interesting and enjoyable.