sound debate if machine head are to be classed by a certain sub genre of metal two things really need to happen there has to be a rationale for the classification in the 'sound debate' sub section they've been considered for about different metal genres at different times so this can't be stressed enough if there is to be a rationale some form of substantiation would most definitely help either a recognised critical opinion or perhaps even the band's own thoughts encyclopaedia's aren't meant to reflect one person's particular opinion