Metallica is one of the most popular rock bands ever.

NPR: Metallica on the Couch

It is ironic that the very band they are trying to emulate probably did not make enough money in their spluttering career to pay for one of the industrial-strength speaker stacks that dominate the skyline whenever Metallica play live.

BBC: Garage Inc - Metallica

Slayer, co-founded by Hanneman and Kerry King, became one of the "big four" thrash metal groups of the 1980s, along with Anthrax, Megadeth and Metallica.

BBC: Jeff Hanneman, Slayer guitarist, dies at 49