 "Classic Rock" has also published, in conjunction with "Metal Hammer", special decade issues featuring 1970s (Issue I), 1980s (Issue II), and 1990s (Issue III) hard rock and metal bands, throughout 2006.In 2007, three special editions were also published with bonus DVDs for £7.50.These each focussed on one genre of rock music - first blues rock (Issue I), then progressive rock (Issue II which has now become a bi monthly magazine due to the popularity), and finally, heavy metal (Issue III).