Out of the three key pioneer groups for heavy rock Deep Purple's infamous Mark II lineup was the most balanced. While Led Zeppelin and Black Sabbath had lead singers who posed as wronged lovers or even miscreant victims of society (especially in Ozzy's case), Ian Gillian had howls and pipes for days, and generally existed on equal footing with Blackmore and Lord. The group's move into arena rock was a mild stunner, but pulled off magnificently, even if the lot of critics took it as self-indulgent chest-thumping. Joke's on them! Up until that time, this may have been THE self-indulgent chest-thumping record to listen to! And it still holds up. I'm not sure - especially on the first side of the record, where you are greeted with three whopper tunes in a row ("Speed King", Bloodsucker", and the operatic-level "Child In Time") - the troika of Gillian, Blackmore, and Lord ever clicked this well in the studio again. Surefire must-hear album!