Complex sentence: Bob Hartman, Greg X. Volz, John Lawry and Mark Kelly, having recorded "Back to the Rock" in 2010, his first studio album with the Classic Petra lineup since "Beat the System" in 1984.
Split into simpler sentences: Bob Hartman, Greg X. Volz, John Lawry and Mark Kelly. This instance of the band recorded "Back to the Rock" in 2010, which was Weaver's first studio album with the Classic Petra lineup since "Beat the System" in 1984.