Heavy metal, or simply "metal" was created by the band Earth. Originally a blues/rock band, the Birmingham quartet moved on to a darker, heavier sound, which became the sound of heavy metal. After Earth, several more heavy metal bands formed, some copying Earth's sound, and others experimenting with other new elements. The bands which gained high popularity and commercial success became the First Wave Of British Heavy Metal, or the FWOBHM. They were Guillotine, Timewarp, Ostrich Foot, Coastal Miner, White Witch and Mercury. Then in 1979, The First Wave Of American Heavy Metal was formed, which was made up of Viper, Goblinslayer, Juggernaut, Ghost, Mantis and The Serpents. Traditional heavy metal became the most popular genre of music and remained so until 1980, when extreme metal was born