"Epic" compositions worth giving a spin

I like good music. Some of it happens to be prog rock. Also yes it was/is the furthest thing with any rock elements from original rock and roll of Chuck Berry and company pretty much by definition. Most rock music falls in between the two somewhere. So its a continuum of styles ie all shades of grey from rock and roll to prog rock, not black and white.

Neither extreme forms are all that popular these days. Things have head off in many different directions since the term prog rock was originally coined.

Viva la music!

Personal favorites listed below, some already mentioned. You can add to this list any one of 100s of symphonies and tone poems but the likes of Bruckner, Dvorak, Strauss, Mahler, Sibelius, Elgar, Shostakovich, etc....the list goes on and on.

Camel: Snow Goose….
ELP: Pictures at an Exhibition, Tarkus and Karn Evil 9
Pink Floyd: Dogs, Echoes, The Wall, Atom Heart Mother Suite
Jethro Tull: Thick as a Brick
RUSH: 2112, Cygnus X-1 Book I: The Voyage and Book II: Hemispheres,
RUSH: La Villa Strangiato, The Fountain of Lamneth, Xanadu
Genesis: In This Cage->Afterglow, Supper’s Ready
Genesis: Cinema Show, The Battle of Epping Forest
Queensryche: OPERATION MINDCRIME
YES: Gates of Delirium, The Revealing Science of God, Close to the Edge:
Dream Theater: Six Degrees of Inner Turbulence, Change of Season, Octavarium
Dream Theater: In the Presence of Enemies, Metropolis Pt. 2
Supertramp: Fool’s Overture
Spock’s Beard: The Great Nothing, The Water
Green Carnation: Light of Day/Day of Nothing
Keith Jarrett: The Vienna Concert, The Kohn Concert, etc…
master of long improvisations on themes spanning entire concerts
Pat Metheny Group: The Way Up:
SOLARIS: Marsbéli Krónikák (Martian Chronicles)
SOLARIS: Nostradamus: Próféciák könyve (Nostradamus: Book of Prophecies)

Forgot to include the following;

ELOY: Land of No Body, The Light from Deep Darkness, Poseidon's Creation, 
"Atlantis' Agony at June 5th - 8498, 13 p.m. Gregorian Earthtime", The Apocalypse,
Reflections from Spheres Beyond, The Answer

Do Spocks Beard "Snow" and the Who "Quadraphenia" count?

Nutty, the original idea was one LP side, more or less.

I'm impressed with the number of contributions (some of which are actually longer than described, but it's still fun, right?).  Glad to see Procul Harum's "In Held 'Twas in I" get a mention.  Anyway, I'm grateful for more leads than I could ever hope to follow up.