Echoes - Pink Floyd (1971)
Pink Floyd is known for its concept albums. From the struggles of everyday life and madness in Dark Side of the Moon; on to the Orwellian drama of Animals; the earth-shattering magnum opus of Fruedian isolation that is The Wall; through to the minor classic on post-World War II life that bowed out Roger Water on The Final Cut. However, the seeds for all of these album- length masterpieces were sewn on the Meddle Album with this side-long track. Think of it as a prequel to Dark Side, as it carries many of the same themes, and focuses on melodicism much more than any previous Floyd work. This is theatre of sound in the grandest sense, which must be why Andrew Lloyd Webber copped a section of it right down to the 12/8 time signature for the opening of "Phantom of the Opera".
I cannot recommend the Live at Pompeii DVD enough. Here is "Echoes" presented in its greatest live performance, at an empty Roman Colosseum...... stunning! So good The Beastie Boys paid tribute to it in their Gratitude video.
Also, visit the Internet Archive for an incredible set of the Decemberists' one date "Long And Short Of It Tour" in which they encore with an impeccable version of this epic composition.