My favorite genre! I've heard something by all the bands this time. (I also saw ELP in concert, but I've become less enamored of them--mostly because of Keith Emerson--I missed the Nice, btw, and Atomic Rooster; heard a bit of the Strawbs--they're coming out with a new album!!!!!).
Between Manfred Mann and Manfred Mann's Earth Band was Manfred Mann Chapter Three. They had two albums (I only know the first one well--titled "Chapter Three (1969)." It's one of the best albums of any genre. It's jazz-imbued prog rock, very similar to Steely Dan, but a little less polished. Lots of late-night solace through the 70's.
My favorite Traffic album is Low Spark.... It's the closest to my beloved Canterbury prog of anything not directly associated with that school. Elegantly wandering but never directionless--always exploring new and fascinating paths.
I'm working on a Riff series on Canterbury classics. Hope to have some articles up by the end of December.
I just noticed that the phrase "Elegantly wandering but never directionless--always exploring new and fascinating paths" fits the style of your personal essays as well. As pleasurable and surprising as a Robert Fripp solo.