As I said in my edit summaries consistency between articles matters Thats how Wikipedia works and lists are not an exception to this rule Even if several references call System of a Down a nu metal band it does not mean it should be included in the list Other sources clearly say this band is not a nu metal see here Also several sources used in this list are not reliable and I really dont see what makes this first source this second source or this third source a clearly Googled search which doesnt even say the band  is a nu metal band reliable This list really needs some clean up anyway