The most archetypal classic Progressive Rock?

I few years ago, I was asked by a work colleague what is progressive rock. I decided to answer this question with an example. After a considerable amount of thought about possibilities, I decided that the classic period prog groups were too original sounding for any to be considered definitive, so I eventually chose the retro-prog album Wobbler - From Silence to Somewhere. I felt that the relatively unoriginal retro-prog would blend together the distinct styles from the classic period and later to form music that is truly definitive of the core of progressive rock. Also, despite being somewhat unoriginal, Wobbler - From Silence to Somewhere is a great album, so that one could decide if progressive rock is for them by listening to Wobbler - From Silence to Somewhere.

I say Yes and Genesis.

Yes

ELP
King Crimson
The originators.

Tull - who probably did more diversification in sound than any of the others.

Yes

Edited by David_D - 5 hours 30 minutes ago at 13:25

KC
Yes
genesis

Of these.

The Moody Blues oft neglected but really deserve more.