Overkill is an American thrash metal band, formed in 1980 in New Jersey. They have gone through many lineup changes, leaving bassist D.D. Verni and lead vocalist Bobby "Blitz" Ellsworth as the only constant members. The band's current lineup includes Verni, Ellsworth, Dave Linsk on lead guitar, Derek Tailer on rhythm guitar and Jason Bittner on drums. Along with Nuclear Assault and Anthrax, the latter of whom would feature one-time Overkill lead guitarist Dan Spitz, the band is one of the most successful East Coast thrash metal bands, and they are often called "the Motörhead of thrash metal", based on their unique playing style, which was influenced by punk rock and the new wave of British heavy metal (NWOBHM). The band has a notable mascot named "Chaly" who has appeared on many of their album covers.

Anthrax is an American thrash metal band from New York City, formed in 1981 by rhythm guitarist Scott Ian and bassist Dan Lilker. The group is considered one of the leaders of the thrash metal scene from the 1980s and is part of the "Big Four" of the genre, along with Metallica, Megadeth and Slayer. They were also one of the first thrash metal bands to emerge from the East Coast. The band's current lineup consists of Scott Ian, drummer Charlie Benante, bassist Frank Bello, vocalist Joey Belladonna and lead guitarist Jonathan Donais. Anthrax's lineup has changed numerous times over their career, leaving Ian as the only constant member of the band. Ian and Benante are the only two members to appear on all of Anthrax's albums, while Bello has been a member of Anthrax since 1984, replacing Lilker.