Discovery really represented ELO's foray more fully into pop based music, and particularly disco. It wouldn't land under prog were it not for their previous catalog.
Let me say upfront that this is not Electric Light Orchestra's best, not by a lot. Also, if I were judging just on this album, it wouldn't go under prog.
I’m a big fan of ELO. I have to admit that the super-star period of A New World Record and Out of the Blue is probably my favorite period of the band’s history.