Speed metal

Speed metal is an sub-genre of heavy metal music that originated in the late 1970s from NWOBHM and hardcore punk roots. It is described by "Allmusic" as "extremely fast, abrasive, and technically demanding" music.
Motörhead is often credited as the first band to invent/play speed metal. Some of speed metal's earlier influences include Deep Purple's "Fireball" and Queen's "Stone Cold Crazy" (which was eventually covered by the thrash metal band Metallica), from their 1974 album "Sheer Heart Attack", and Deep Purple's song "Highway Star", from their album "Machine Head". The latter was called 'early speed metal' by Robb Reiner of speed metal band Anvil. Led Zeppelin's "Communication Breakdown", first released in January 1969, could also be said to be an early template for speed metal as mentioned in Mac Randall's.
Speed metal eventually evolved into thrash metal. Although many tend to equate the two subgenres, there is a distinct difference between them. In his book "", Ian Christe states that "...thrash metal relies more on long, wrenching rhythmic breaks, while speed metal... is a cleaner and more musically intricate subcategory, still loyal to the dueling melodies of classic metal."