Bruce Frohnen has an essay over at TIC about ELP, arguing that they are “the most important musical group of the rock era.” Here’s part of his argument:
“Karn Evil 9” is not overblown, it is genuinely and intentionally music on a grand scale, combining classical techniques with multiple, interlacing rhythms, and polyphony to immerse the listener in a web of sound that for a time creates its own reality.
“Counterpoint” is a concept (not to say a reality) little understood among most rock musicians; but it was crucial to ELP’s ability to produce sounds that made sense at a level frankly higher than can be achieved in most blues-based music, with its emphasis on a single, simple melody underscored by rhythms deeply rooted in a single beat. At their usual best, Emerson, Lake, and Palmer performed according to a vision of rock music as rooted in the classical past. They produced both direct classical adaptations (“Fanfare for the Common Man” being the most famous) and original compositions that likewise combined modern rhythm and technique with melodic sophistication to create genuine art—pieces of beauty capable of affecting the souls of listeners.