Very comprehensive, if somewhat dry, account of the groundbreaking British heavy metal group's history. The author digs up some interesting information about the band's formation I did not know, such as the fact the band was originally meant as a revolving door supergroup of session musicians but the line-up stuck. Or the fact that at first the band was categorized as part of the same progressive rock scene as The Moody Blues and Procol Harum, hence marketed to the same audience. The members did not feel comfortable with this, as they felt closer to harder acts like the Jeff Beck Group, Cream or the Yardbirds. This goes a long way to explaining the less progressive and much heavier direction the band started taking from their S/T third album from 1969 onwards.
Heatley also does a good job of explaining the different music backgrounds of the various individual members Deep Purple have come from, and how this resulted in their innovative music style combining disparate genres as well as the constant feuding between the musicians involved, in particularly Ritchie Blackmore vs most of the vocalists in particular Ian Gillan.
Another interesting part of this book is the information about which other British rock groups of their generation that Deep Purple have shared members with - not just the better known ones like Rainbow or Whitesnake but also say Trapeze and Ian Gillan's solo records.