have we seen this kind of thing before?

Here are two different versions of the same song, "Jackie, Dressed in Cobras," written by Dan Bejar. The first version, by Destroyer, comes from a split single with Black Mountain issued in late 2003. The second version, of course, is from The New Pornographers' Twin Cinema.

Destroyer's version, partially because it came first but also because of its more sparse arrangement and less glossy surface, ends up sounding like a demo of sorts. I didn't think of the song that way when I first heard it, but listening to the two tracks consecutively, the effect is nearly inevitable. This version lacks that cool piano part, derived from the tricky rhythm in the part after the chorus (on the lines "wrapped on the jungle floor"), which shows up in The New Pornographers' version after the second verse. There's also something tentative about the move to a new chord ("on a train devouring the land") compared with the remake. I think it's because the bass note on the Destroyer version isn't the root, and so the chord sounds a bit indefinite, whereas The New Pornographers punch out the chord so it feels like the entry of a new section of the song. Finally, the newer version adds that sort of "Ticket to Ride"-like electric 12-string lick in the intros to the verses.

Then again, the remake lacks the spooky feeling that comes from the freakishly long reverb soaking the original...and overall, the songs are almost completely different in mood (not to mention key: for some reason - a capo? - the Destroyer version is in the somewhat odd-for-guitar key of B-flat, while the New Pornographers' version takes it down to the easier-to-play key of A).

Destroyer "Jackie, Dressed in Cobras"
The New Pornographers "Jackie, Dressed in Cobras"