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 post some more of the same kind.
Anyway, here're most of the "songs" from the poll series:
Ange - "Les Longues Nuits D'Isaac" (1974)
Area - "Luglio, Agosto, Settembre (Nero)" (1973)
Area - "Gioia e Rivoluzione" (1975)
Banco del Mutuo Soccorso - “Canto Nomade per un Prigioniero Politico" (1973)
Curved Air - "Marie Antoinette" (1972)
Eloy - "The Light from Deep Darkness" (1974)
Eloy - "Plastic Girl" (1974)
Emerson, Lake & Palmer - "Lucky Man" (1970)
Emerson, Lake & Palmer - Tarkus (1971)
Emerson, Lake & Palmer - Karn Evil 9 (1973)
Flower Travellin' Band - "Hiroshima" (1972)
Genesis - "The Knife" (1970)
Genesis - "Get 'Em Out by Friday" (1972)
Genesis - Supper's Ready (1972)
Genesis - "Dancing with the Moonlit Knight " (1973)
Gentle Giant - "Proclamation" (1974)
Henry Cow - "Industry" (1979)
Jethro Tull - "Aqualung" (1971)
Jethro Tull - "Cross-eyed Mary" (1971)
Jethro Tull - "Wind-Up" (1971)
Jethro Tull - Thick as a Brick (1972)
King Crimson - "21st Century Schizoid Man" (1969)
King Crimson - "Epitaph" (1969)
Magma - "De Futura" (1976)
Marillion - "Forgotten Sons" (1983)
Marillion - "White Russian" (1987)
Niemen Aerolit - "Cztery Sciany Swiata" (1975)
Pink Floyd - "Money" (1973)
Pink Floyd - "Dogs" (1977)
Premiata Forneria Marconi - "Mr. 9 'till 5" (1973)
Triana - "Rumor" (1977)
Van der Graaf Generator - "The Emperor in His War-Room" (1970)
Van der Graaf Generator - "Pioneers Over C" (1970)
Van der Graaf Generator - "Childlike Faith in Childhood's End" (1976)
Rick Wakeman - "The Prisoner" (1976)
Roger Waters - "Amused to Death" (1992)
Wigwam - "Pedagogue" (1974)
Yes - "Yours Is No Disgrace" (1971)
Yes - "I've Seen All Good People" (1971)
Yes - "The Gates of Delirium" (1974)
Frank Zappa - "Uncle Remus" (1974)