 While the attention devoted to the NWOBHM bands waned , a new succession of far less mainstream metal subgenres began to emerge and attract many British metalheads . Power metal and thrash metal , both stemming from the NWOBHM and maintaining much of its ethos , were gaining critical acclaim and commercial success in the second half of the 1980s with their even faster and heavier sound . Bands such as Helloween , Savatage , Metallica , Slayer , Megadeth , and Anthrax captured much of the market share of those metalheads who were not content with the sound or style of more mainstream , pop @-@ oriented metal bands . 
