Metal Memes

I think most tracks are, especially most old ones. Some others are more like rock ballads or power ballads etc.. I think that's normal and a good thing. When you listen to an album, you don't want it to be an hour of pure headbanging. Most metal bands have some songs that are more rock than metal and that's also true for other genres. I'm not surprised to find bossa nova or salsa on a jazz album or a blues band playing some swing.