This soundtrack, perfectly suited to an independent documentary about the growing effects of commercialization on an isolated community in the Aleutians, gives icy breath to some pretty heavy-duty atmospheric explorations. Under the guise of “The Boxhead Ensemble,” the project involves a host of Chicago-area musicians, including Rick Rizzo (11th Dream Day), Jim O’Rourke and David Grubbs (Gastr Del Sol), and Will Oldham (Palace). Although the music is clearly improvised, it reveals considerable forethought in both composition and execution. The individual tracks, each bearing the indelible marks of its contributors, have enough in common that in its entirety the album coalesces into a fluid aural collage that unnerves and unsettles with eerie grace. O’Rourke’s spacious, meditative contributions are among the most distinctive tracks, and his collaboration with Oldham on the disc’s only vocal offering, “Ebb’s Folly,” is the soundtrack’s high point. Oldham’s world-weary lyrics, nestled amid burgeoning electronics, convey the simple sorrow of a bygone era, while O’Rourke’s subtle keyboard manipulations temper the mood with understated rumblings. The improvisatory noodlings of Grubbs’ piano and Charles Kim’s guitar on the three-movement “The Valley” convey a quiet sense of disorder while conjuring up a landscape of nonstop variety, an indication that the soundtrack is well worth listening to for its own merit, let alone as a complement to the film.—Amy Domingues