Renaissance history is complex—the band as much as its namesake era. The prog-rock act sprouted from the ashes of a Yardbirds offshoot in mid-1969, only to swap out its members so frequently that, by 1972, they were a completely different group. Prologue , then, is essentially the debut album of their definitive period, with future leader/guitarist Michael Dunford contributing as a hired-gun songwriter and arranger. His elegant compositions—drawing from classical, folk and jazz more than rock—offer an ideal framework for the operatic, glass-shattering voice of Annie Haslam, often anointed the “Prog Rock Queen” by genre die-hards. Renaissance were a band in flux on Prologue , and some of the material (like the hazy “Kiev,” fronted by bassist Jon Camp) feels cautious compared to the fullflowered symphonic-level genius of their mid-‘70s work. But at its peak, the LP rivals any progressive rock of the early decade: The title cut finds Haslam unfurling an expressive “do do do” vocal over a cinematic jazzrock groove; and the eerie “Rajah Kahn” allows the quintet to stretch out and explore their darker side, weaving wild synthesizer solos (courtesy of Curved Air’s Francis Monkman) and tabla rhythms into an 11-minute epic. Esoteric’s reissue is essential for the remastered sound, even if bonus tracks are basically nonexistent. (Who wants to hear a single edit of “Spare Some Love” when you can check out the real thing?) But it’s worth taking any excuse to immerse yourself in this minor classic.