Spee metal is a sub-genre of heavy metal music originating in the early 1980s that was the direct musical progenitor of thrash metal. When speed metal first emerged as a genre, it increased the tempos that had been used by early heavy metal bands such as Led Zeppelin, Black Sabbath, and Deep Purple, while retaining their melodic approaches. Many elements of speed metal are rooted in the music of UK's NWOBHM bands while fusing their stylistic approach with the music of 1970's punk rock