If you query veteran metalheads about Sabbath Bloody Sabbath, either they'll say it's the classic line-up's last great album or their first non-great one. The appearance of Yes keyboardist Rick Wakeman on the intricately arranged "Sabbra Cadabra" betrays the band's desire to create an album that is less brutal and more progressive. Nearly as ambitious are "A National Acrobat" and "Killing Yourself to Live," both of which boast densely layered guitars and all manner of atmospheric effects. Meanwhile, the Moog-heavy "Who Are You?" is quite possibly the birth of European-style baroque metal.