I have a soft spot for ELP, as Pictures At An Exhibition was one of the few rock LPs in my Dad's otherwise entirely classical LP and CD collection. I've gone the other way, and I enjoy far more classical music now than I did back then. ELP's take on Pictures is at times wooden, leaden and lacking in dynamics. There is a staunch arrogance in throwing away over half of Mussorgsky's original composition, adding a pointless acoustic interlude, and offensive Hammond organ feedback jam and Moon/June/Spoon lyrics to The Great Gates of Kiev. Crediting various tracks to Mussorgsky/Emerson is equally galling. Yet, like Yes, there is something to be said for over confident middle class English dudes in their early 20s that meant that they could push that stuff out there, and ELP were all accomplished musicians. If anything I think Greg Lake was the weak link in that band. I detect a distinct lack of musicianship in his playing, though he had a very nimble pick technique. I've heard more than one live recording where his bass is audibly out of tune, and I feel he was often left to simply learn Emerson's left hand arrangements. His singing voice is impressive, but again it is raw and untrained and could sound pretty ragged on live recordings.
Then the band discovered cocaine and started their gigs with Pirates at 180 bpm. Great fun I'm sure, and you have to admire a band that could turn Mussorgsky's music into a stadium-grabbing live staple. If nothing else, a lot of kids were probably put onto classical music.
I prefer some of Emerson's playing in The Nice, when he could still do a good Jimmy Smith impersonation. Lee Jackson's voice is an acquired taste, as his rubbery Vox bass somehow doesn't fit in the music so well. Brian Davidson was a vastly underrated drummer with a great swing and jazz feel; two attributes entirely missing from Carl Palmer's stiff playing. If you must be a stiff proggy drummer, at least add all the flashy temple bells stuff like Neil Peart. Carl Palmer seems like an orchestral percussionist trapped at the back of a rock band.