Socially-engaged major Progressive Rock

I've been thinking that it could be interesting to have a thread about the socially-engaged "songs" included in the poll series "Thinking politically / socially-engaged songs", and I can tell now that my selections have mainly focused on major Prog. Also in this new thread, you can mention some more of the same kind, including whole albums if they're more or less socially-engaged in their entirety.

Anyway, here're most of the "songs" from the poll series (Edit: plus some of those (including entire albums) mentioned in other threads of the same theme and in this thread):

Ange - "Les Longues Nuits D'Isaac" (1974)

Area - "Gioia e Rivoluzione" (1975)

Curved Air - "Marie Antoinette"  (1972)

Eloy - "The Light from Deep Darkness" (1974)

Genesis - "The Knife" (1970)

King Crimson - "21st Century Schizoid Man" (1969)

According to Edward Macan's Rocking the Classics, Roger Waters explores in this album those sides of the modern industrial society that depersonalize, dehumanize, and ultimately drive people to madness: time, or more accurately, industrial society's conception of it, money, war and violence ("Us and Them"), and the futility of the nine-to-five work life ("Breathe" and "On the Run") (1997, p. 78). 

This interpretation is quite in agreement with Wikipedias view of this album ( https://en.wikipedia.org/wiki/The_Dark_Side_of_the_Moon# ).