A very small ammount of people fit into this category. Your average highschool would have four or less of them at most, seeing as most people who listen to "metal" actually listen to Alt. Rock/Nu metal. Metalheads are usually spotted by their looks. Usually denim jeans (Blue or black), band shirts, long hair/shaved hair, etc. The metalheads truely are the stupidest group of people to pick a fight with, we may be the quiet type, but metalheads could easilly wipe out multiple kids, and have a short temper that goes along with that. The metal culture however has dropped quite a bit, seeing as how the "hip" thing is to listen to rap or numetal.
Real metal bands: Iced Earth, Judas Priest, Amon Amarth, Bathory, Morbid Angel, Manegarm, Hammerfall, Blind Guardian, Burzum, Borknagar, Emperor, Immortal, Einherjer, Finntroll, etc
NOT metal bands: Korn, Slipknot, Mudvayne, Godsmack, Limp Bizkit, etc