ELP, until they jumped the shark with Love Beach (or, arguably, Works II)
Uggghhh .. yep, yer right.
I saw ELP in 1977 at MSG for the "Works volume I" tour, complete with a 70 piece orchestra, which got so expensive for them to take on the road with them that they were forced to fire the orchestra after that concert ... a shame really, it was a great show :)