The Deep Purple epics

a lot of songs in the poll don't fit the epic description, 

but if by epic, it's just a long(er) song, then, yes, but if it's a long song telling a story, then a lot of songs don't fit here. 

Speaking of which, there's a very strange music video for April, recorded in October 1969 for West German broadcast. There are a number of unusual things about it:

-the video is shot in a quarry for some reason

-the video features cuts to military trucks filled with shirtless young men wearing shorts/trunks (?!)

-truck noises are spliced on the track whenever the scene shifts to the trucks

-a small orchestra is gradually assembled, with workers adding chairs during part 1, the orchestra plays part 2 and the orchestra leaves when part 3 starts

-workers lay out chairs for the orchestra in part 1 and remove them during part 3

-the music is obviously the studio recording (most obvious because part 1 features both acoustic and electric guitar from Blackmore), so one wonders why they had a small orchestra assembled just to mime along to the music

-save for a brief moment during the outro guitar solo, you can't see Blackmore except for the neck of his guitar

-April is a Mk I song recorded with Evans and Simper, whereas the band was in it's Mk II lineup with Gillan and Glover at the time the video was recorded

-Gillan seems to be smoking a cigarette during the orchestral section

-the band and orchestra are both facing away from the camera

Per the YouTube uploader, the video was recorded for an avant garde film, P2, by Werner Schretzmeier and Juergen Schmidt-Oehm. The film is 47 minutes long and also features the band playing And The Address and Hey Joe. The film also includes performances by Steppenwolf and Savage Rose.

It's Mistreated for me.