Not the biggest ELP fan, but the song “Trilogy” is one of the most awesome songs ever done.
I found an interesting Jazz-tinged interpretation here...
https://www.youtube.com/watch?v=xNxoIDPoURY
ELP is my favorite band, and Trilogy is my favorite ELP album. The Endless Enigma from Trilogy was actually covered by another band, Mastermind, and they do a really good job.
I can't believe you mentioned this! I came across this Jan & Den cover by accident a couple of years ago and immediately burned it to my iPod. I think it might be as good/well, different-better than the original. She does an amazing scat of Emo's synth solo. Plus she's "bangs" hot. Piano player is good too, although a bit repetitive in the licks dept.