Sin After Sin is the third studio album by English heavy metal group Judas Priest, originally released in 1977. The album represented several major milestones in the group's career; the band made their major label debut and were able to work with a famous musical artist as their producer, former Deep Purple member Roger Glover. The band also fully embraced an aggressive metal sound with this release, significantly toning down the arena rock and blues rock influences shown in their past work, and the group achieved widespread popularity on the radio stations for their first time, oddly enough with their hard-edged version of Joan Baez's song "Diamonds & Rust".