In 1981, Iron Maiden released their second studio album, "Killers". Containing many tracks written prior to their debut release, only two new songs were written for the record: "Prodigal Son" and "Murders in the Rue Morgue" (the latter's title was taken from the short story by Edgar Allan Poe). Unsatisfied with the production on their debut album, the band hired veteran producer Martin Birch, who would go on to work for Iron Maiden until his retirement in 1992. The record was followed by the band's first world tour, which included their debut performance in the United States, opening for Judas Priest at The Aladdin Casino in Las Vegas.