Deep Purple: Knocking at Your Back Door - Best of Deep Purple in the 80s (CD) VG This product is a CD titled "Knocking at Your Back Door: The Best of Deep Purple in the 80's" by the artist Deep Purple. Released in 1992 by Mercury Records, the CD features the best hits from the 80s era of the band. Produced by Roger Glover and Deep Purple, the album showcases the band's hard rock style with a runtime of 65 minutes. This CD is a must-have for fans of classic rock music, especially those who appreciate the work of Deep Purple during the 80s.