When I first really found my footing in popular music listening, it was in the vast soundscape of 1970s progressive rock. I didn’t really understand what exactly I was hearing when I listened to Yes or Emerson, Lake & Palmer (or, later, when venturing into darker waters with King Crimson), but it truly captured my imagination. On Wednesday, one of the pillars of that genre, Greg Lake, lost his battle with cancer. With Robert Fripp, a childhood friend, Lake founded King Crimson, the ur-band of progressive rock. Lake then took his considerable vocal talents, along with his bass guitar, and joined on with (the recently late) keyboardist Keith Emerson and later drummer Carl Palmer in ELP, “progressive rock’s first supergroup.” The band’s two-CD live compilation, King Biscuit Flower Hour: Greatest Hits Live, was in heavy rotation in my car stereo and, once I expanded my radio-format horizons at WHCL, on the airwaves. The second disc contains only one song, and I used a portion of it for the intro to every show. The full version, recorded at a live concert performance in Anaheim in 1974, constitutes today’s Jam: