Fast, heavy guitar riffs, relatively easy bass riffs, double-pedal drumming, insane guitar solos (the good ones are in the right key), usually non-talented vocalists that put on a show to make up for it. Started with Sabbath, which was close to classic rock, then brought to life by Metallica. Since then it has broken into many types, such as thrash (speed), nu-metal, death-metal, black metal, and it pretty much gets worse as the list goes on. Overall not a bad type of music, but lets face it thrash metal died at the end of the 80s.
Steve: Heavy metal kicks ass because of insanely loud guitar riffs and headache inducing drum beats!!
Jimbo: That's why it sucks too.