 These two styles do not exhaust all of the musical influences found in the British metal music of the early 1980s , because many bands were also inspired by progressive rock ( Iron Maiden , Diamond Head , Blitzkrieg , Demon , Saracen , Shiva , Witchfynde ) , boogie rock ( Saxon , Vardis , Spider , Le Griffe ) and glam rock ( Girl , Wrathchild ) . Doom metal bands Pagan Altar and Witchfinder General were also part of the NWOBHM and their albums are considered among the best examples of that already established subgenre . 
