Slayer - Show No Mercy, 1983, FULL ALBUM. Show No Mercy is the debut studio album by American thrash metal band Slayer, released in December 1983 through Metal Blade Records. Brian Slagel signed the band to Metal Blade after watching the band perform the song \"Phantom of the Opera\" by Iron Maiden. The band self-financed their debut album, combining the savings of vocalist Tom Araya, who was employed as a respiratory therapist, and money borrowed from guitarist Kerry King's father.