Progressive Rock originated with the Beatles (White Album etc) although I think Yes would be considered the first Progressive Rock Band. Prog-rock still exists (Dream Theater, Radiohead). Prog-rock rides that fine line between cool and self indulgent. ELP falls off into self-indulgent more than Yes. Lots great bands fall into the category (King Crimson, Mike Oldfield, even the Buggles) but a lot of unlistenable stuff flies the Prog-rock flag.
I jumped in this in the middle – how the heck did a thread about the death of a member of the Ramones turn the corner to Progressive Rock?
“It’s a strange strange world we live in, Master Jack”
justshutupandtakeit argued that the Clash were far superior to the Ramones because, "Talent is the greatest factor in good music." I said it's that sort of thinking that leads to progressive rock, which justshutupandtakeit hates. (I actually like a fair bit of prog-rock ... Yes, Pink Floyd, Genesis ... but none as much as I like the Ramones.)