Lo-fi indie-pop gets a startling makeover in the able hands of Phil Elvrum, the young Washington state producer-musician who fronts the loose aggregate of crunchy creative types known as the Microphones. Over a series of albums and singles, Elvrum has methodically disassembled the idea of the shaggy-haired dude with a busted guitar (i.e., Lou Barlow) and rebuilt it as a perpetual work in progress, exposing the seams in his songwriting and recording both by declining to tie up his records' loose ends and by issuing, dub reggae-style, alternate and isolated versions of instrumental tracks and studio outtakes. It makes for fascinating listening: "The Glow" Pt. 2, a 2001 Microphones CD, careens from gentle folk-pop strumming to full-blown sludge-rock with all the natural grace do-it-yourself music is supposed to promise, and Elvrum reflects that dynamic range in his songs' naked emotional reverberations. Mount Eerie, the Microphones' latest, continues this journey into itself, arriving as a typical CD/LP but also available in drums- and vocals-only editions; it's no less ambitious, either, ostensibly telling a vaguely defined story about self-realization inspired by a mountain located on the tiny island on which Elvrum grew up. Since Elvrum's not a member of Yes, the concept doesn't really take off, but the music here does: five long swatches of sound that fold Elvrum's diminutive croon into his expanding palette of varied guitar tones, throbbing percussion, found-sound collage and near-ambient choral arrangements. "How many times have I made up this song before?" he wonders in "Universe." Several times, actually, but it keeps getting more interesting.