Half a century ago, powered by the huge and ongoing success of their debut single "A Whiter Shade Of Pale," Procol Harum went on to help define the progressive rock genre while at the same time embracing their roots in blues and soul. The band's eponymous debut, issued in the massive single's wake in September 1967, celebrates its 50th anniversary in 2017. Anchored by the tasteful organ work of Matthew Fisher and Robin Trower's steadfast guitar playing, the band incorporates elements of psychedelic rock, blues, and classical with aplomb on signature standouts like "Conquistador," "A Christmas Camel," "Kaleidoscope," "Good Captain Clack" and "Repent Walpurgis."