AllMovie

One of the most popular British hard rock bands of the 1970s, Deep Purple went through a remarkable creative evolution during their first few years as a recording act, going from the obstreperous pop sound of Shades of Deep Purple to the more mature and weighty approach of Machine Head. Rock Review: A Critical Retrospective -- Deep Purple focuses on Deep Purple's career from 1969 to 1972, with musicians and critics weighing in on their work from this period and performance footage illustrating their points. This program was created without the participation or approval of Deep Purple or their representatives.