The resulting is a highlight of British heavy metal. Make no mistake, the LP - and Rainbow - have never been cool in the way that earlier hard rock groups such as Black Sabbath, and some of the later New Wave of British heavy metal bands were. Rainbow's focus on dungeons and dragons-style mythology and medieval mysticism seemed cheesy even in 1975. But the LP has dated extremely well and rocks very hard indeed, abetted by hard-hitting drummer Cozy Powell behind the kit.

A groovy synth line introduces , and then the band are off into a non-stop rifferama topped by Dio's loud, tuneful vocals, Blackmore's concise rock playing, and Powell's thunderous drums. , about groupies, is Blackmore's highlight, with some innovative guitar work that melds eastern scales with rock'n'roll. The LP's twiddly keyboard work, derided at the time, sounds interesting now, and during the 25-minute finale, , Powell bashes hell out of the skins.

Blackmore and Dio finally fell out over the next LP, 1978's Dio went on to join Black Sabbath, before forming his own eponymous band in the 1980s (he died from stomach cancer in 2010). Rainbow spiralled downhill and lost any credibility they had left in 1979 with the release of the ghastly AOR single . Rewinding now, is a reminder of why Blackmore was praised in the same breath as Jimmy Page and Jimi Hendrix back in the early 1970s. Blackmore left the rock scene over a decade ago to focus on new age music in the duo Blackmore's Night, a folky outfit.