• Hair metal: Inspired by 1970s glam bands, hair metal acts like Motley Crue and W.A.S.P focused on big melodies, drinking their own weight in booze and looking like, to borrow a phrase from those days, a bit of a wally. What not to say: “Final Countdown by Europe? Metal doesn’t get much heavier than that.”
• Nu metal: Bands such as Limp Bizkit, Papa Roach and Linkin Park combined their metal with grunge, funk and what is known in musicologist circles as terrible, terrible rapping. What not to say: “Limp Bizkit’s Fred Durst really summed up the anxieties and fears of a lost generation. He was so much more than just a middle-aged man in long shorts grunting.”
• Prog metal: This adopts the bonkers time signatures, technical prowess and geeky lyrical references that made progressive rock so, well, progressive. Mastodon’s recent album, Crack the Skye, incorporates ukuleles, Stephen Hawking references and a four-section symphony about czarist Russia. What not to say: “Can you not just play this one in 4/4?”
• Comedy metal: Because a lot of metal is obviously quite ludicrous (grown men growling loudly about orcs, for instance), it has leaned itself to affectionate parody. Often — as in the case of the recent Anvil! movie — the lines between comedy and reality are pretty thin. See also Spinal Tap, Jack Black and the Darkness. Oh, the Darkness weren’t joking? Oops. What not to say: “Those Napalm Death guys are just so funny!”
• Other genres: Symphonic metal, sludge metal, stoner metal, drone metal, ambient metal, viking metal, power metal, groove metal, glam metal, gothic metal, alternative metal, aluminium, copper, zinc, tin, alloy, and carbon fiber.



