Trohman became involved with the Chicago hardcore punk scene, with his first band being Voices Still Heard he formed with friends. At the age of fifteen he taught himself how to play guitar, and at age sixteen, he joined local band Arma Angelus and spent a summer touring as the group's bassist. He developed a friendship with the group's singer, Pete Wentz, and the pair discussed forming a more melodic band influenced by groups such as Green Day. Trohman then met Patrick Stump in a Borders bookstore, and recruited him to join the band, which was subsequently named Fall Out Boy.