The Cedar Hill Refugees are not a band but a one-off gathering of Nashville and Uzbek -- yes, you read that right -- musicians assembled to play Anglo-Celtic and American folk songs, plus a few in-the-tradition originals, with Uzbek accents. Huh? I can hear you gasping all the way from where you sit.

I know a fair amount about the Anglo-Celtic-American tradition, nothing about Uzbekistan's. (Uzbekistan is one of those countries known broadly and vaguely to Americans as a "former Soviet republic.") On Pale Imperfect Diamond the band Jadoo represents that nation on native vernacular instruments, including the karnay (a long trumpet with a mouthpiece), accordion, reeds and percussion.

As one struggles for a more familiar frame of reference, one thinks of the Chieftains, who have occasionally collaborated with American country and folk artists and of whom Jadoo is arguably the former Soviet-republic equivalent. Of course, the link between Irish and American traditions, especially those of the Southern mountains, is well known and detectable even to the untrained ear. On the other hand, the notion of Appalachian-song patriarch Ralph Stanley's performing an African-American spiritual ("Keys to the Kingdom") in an Uzbek-flavored arrangement surely boggles the imaginative capacity of just about anybody. To grasp how it's done, you have no option but to listen. Once you've heard it, you'll thank me for that advice. Defying instinct and even common sense, the collaboration succeeds marvelously.

The project is the brainchild of Jack Clift, who was somehow reminded of American hillbilly music when he first encountered Jadoo. In due course, he and co-producer John Carter Cash rounded up a variety of roots-conscious country singers and pickers, the most prominent of them Marty Stuart, Ron McCoury (mandolinist with his father Del McCoury's popular bluegrass band), the Peasall Sisters (of O Brother note), guitarist Randy Scruggs and many more.

I would have bet that nobody in Nashville, including artists I like and admire, had ever heard of "The Wife of Usher's Well" (one of the scariest of the Child ballads) or "Stormalong" (a rarely recorded 19th-century sea shantey), but I would have lost. And, I might add, been happy to do so, given what I hear here. I would also have thought that John Renbourn, the pioneering British folk-revival guitarist, was unknown in Music City, but that's his version, not (as one would have anticipated) Bill Monroe's-via-Charlie Poole's, of the old McKinley-assassination broadside "Whitehouse Blues." It has to be, because no other has that melody or the "hard times, hard times" refrain, which I am reasonably certain is a Renbourn invention. That song opens the album, setting up high expectations, all of them met in what follows.

Toward the end, things get even weirder with an arrangement of "Wildwood Flower," the Carter Family signature song (in its first incarnation an 1860s parlor ballad) long a country-music cliche, radically unlike any with which heretofore you have been in hearing distance. The wild reading of the Tennessee folksong "Sailaway Ladies" sometimes gives the impression of having arrived from outer space.

Beyond that, the handful of originals, penned by Clift with varying collaborators, all hold their own. The title song and "Colors of the Sky," an appealing take on the often-visited folk theme of restless rambling, conjure up rich atmospheric soundscapes. The Peasalls's genetic harmonies exhume the graveyard soil of "Usher's Well," at once chilling and (if uneasily) charming the listener. I have never heard a version like it, but then, I could say that about everything else on this unforgettable recording.