by Lindsay PlanerAs the Beatles' Sgt. Pepper's Lonely Hearts Club Band (1967) had done a year earlier, Super Session (1968) initially ushered in several new phases in rock & roll's concurrent transformation. In the space of mere months, the soundscape of rock shifted radically from two- and three-minute danceable pop songs to comparatively longer works with more attention to technical and musical subtleties. Enter the unlikely all-star triumvirate of Al Kooper (piano/organ/ondioline/vocals/guitars), Mike Bloomfield (guitar), and Stephen Stills (guitar) -- all of whom were concurrently "on hiatus" from their most recent engagements. Kooper had just split after masterminding the definitive and groundbreaking Child Is Father of the Man (1968) version of Blood, Sweat & Tears. Bloomfield was fresh from a brief stint with the likewise brass-driven Electric Flag, while Stills was late of Buffalo Springfield and still a few weeks away from a more or l...