A subgenre of metal music, considered by many to be the original extreme
metal genre. It essentially began as a derivative of speed
metal, played by bands like Motorhead and Overkill. Thrash
metal took the high speed aspect of such bands, and added NWOBHM influenced melodies, and more progressive elements to the music.
Thrash
metal's origins trace back to the early 1980's, and San Fransisco is considered the birthplace of most of the thrash greats. Thrash
metal bands include Metallica, Megadeth, Slayer, Anthrax, Testament, Exodus, Kreator, etc. It has proved to be very influential to almost every metal style that has come about since it's inception, and has experienced somewhat of a popularity revival in recent years.
Dude 1: *Slayer playing in the background* Man, Thrash metal fucking owns! what the hell happened to bands like this?
Dude 2: Uh, I'm going to go see Megadeth in 2 weeks..
Dude 1: ...You bastard!