The song Machinery Of Torment was composed by Rage Against The Machine guitarist Tom Morello, who also serves as executive music producer for the movie.
The phrase "Metal up your ass", from the promotional posters, is in reference to the original November 1982 Metallica demo tape that bears a hand holding a sword, protruding out of a toilet.
Glen Sobel, touring drummer for Alice Cooper was tasked with teaching actor Jaeden Martell how to play drums for the movie.
The metal homework song list Hunter gives to Kevin is:
"War Pigs" Black Sabbath
"Ace of spades" Motorhead
"The Trooper" Iron Maiden (live)
"Aces High" Iron Maiden
"Exciter" Judas Priest
"Unchained" Van Halen
"For Whom the Bell Tolls" Metallica
"Holy Diver" Dio
"Mr Brownstone" Guns n' Roses
"Holy Wars" Megadeth
"War Ensemble" Slayer
"Im Broken" Pantera
"Rattamahatta" Sepultura
"Killing in the Name" Rage Against the Machine
"I Am the Black Wizards" Emperor
"Psychosocial" Slipknot
"Schism" TOOL
"New Millenium Cyanide Christ" Meshuggah
"The Lepper Affiinty" Opeth
"Blood and Thunder" Mastodon
"Laid to Rest" Lamb of God
"Hail to the King" Avenged Sevenfold
"L'Enfant Sauvage" Gojira
"Mjod" Kvelertak
Hunter's name in D&D is "Malmsteen of Gorgoroth". Yngwie J. Malmsteen is a renowned neoclassical metal guitar player, while Gorgoroth is a Norwegian black metal band.