*** VARIOUS ARTISTS, “O Brother, Where Art Thou?” soundtrack, Mercury

With the wealth of actual archival music available from the rural Depression-era setting of the Coen brothers’ latest movie, it wasn’t really necessary to have current artists re-create the sounds.

The only recording on this album that existed at that time is Harry McKlintock’s 1928 “Big Rock Candy Mountain,” and even an “authentic” chain-gang chant and a Stanley Brothers track are of ‘50s vintage.

But movies aren’t reality, and the Coens’ off-kilter, quasi-mythic viewpoint relocate Homer’s “The Odyssey” in time and place, so it’s all relative.

In any case, soundtrack producer T Bone Burnett went to the right people for romanticized nostalgia. Gillian Welch, Alison Krauss, John Hartford and Norman Blake. The blues, bluegrass, gospel and period novelties they and others offer, mirror the film’s odd, epic quests for redemption.

The best new track blend of authenticity and myth, with the siren trio of Emmylou Harris, Krauss and Welch angelically singing a lullaby over devilishly spooky backing. Most others are straightforward: Blues guitarist Chris Thomas King, acting on screen as a Robert Johnson-like figure, gives a believable “Hard Time Killing Floor,” and the film’s fictional Soggy Bottom Boys (with actor Tim Blake Nelson singing one track) almost sound right off a 1937 radio broadcast. Almost. This is not reality. But it’s a darn good fable.

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Albums are rated on a scale of one star (poor) to four stars (excellent). The albums are due in stores Tuesday.