Refused is a Swedish hardcore punk band originating from Umeå and formed in 1991. Refused is composed of vocalist Dennis Lyxzén, guitarist Kristofer Steen, drummer David Sandström, and bassist Magnus Flagge. Guitarist Jon Brännström was a member from 1994, through reunions, until he was fired in late-2014. Their lyrics are often of a non-conformist and politically far-left nature and were for a time associated with the straight edge subculture.

Karl Johan Schuster, known professionally as Shellback, is a Swedish record producer, songwriter and multi-instrumentalist. Shellback was listed as the No. 1 producer of 2012 on Billboard magazine's year end chart, and he also topped the list of their "Top 10 Songwriters Airplay Chart" the same year; he has won four Grammy Awards.