When rock musicians "rediscover" the blues, it usually means one of two things: They feel a need to step back from their careers and look at one origin of their craft, or they've run out of ideas and need to give writer's block a swift kick in the pants.

It seems as if Doug Martsch has found himself at this crossroads with his first solo album, "Now You Know." The brains behind Boise, Idaho's best (if only) indie band, Built to Spill, has put his patented lo-fi shriek on the back burner and picked up the slide guitar-style of Delta blues. Recorded in Martsch's basement studio, "Now You Know" came together after Martsch discovered musicologist Alan Lomax's 1959 recordings of bottleneck guitar great Mississippi Fred McDowell.

So has Martsch traded in his ratty jeans and Gen-X sneer for dark glasses, a porkpie hat and a dingy room on Bourbon Street? Hardly. "Now You Know" has one foot firmly planted in alt-pop sentimentality while the other lands in the Louisiana marshes. It's blues filtered through the lo-fi idiom. The opening track, "Offer," is about as far down South as he goes. "I am everyone that someone used to love," Martsch bleats, his frail, nasally whine wavering over a slippery slide guitar a la Ry Cooder.

Sparsely accompanied by bass, drum or cello, Martsch sticks mostly to acoustic, down-tempo gems of loss and self-realization. The album's only misstep is the cover of McDowell's "Woke Up This Morning (With My Mind on Jesus)," a stretch for anyone to play who isn't old, black and from the South.

This new direction from Martsch may only be a fleeting, front-porch interlude during Built to Spill's hiatus, but his solo effort adds further evidence that yes, young, white suburbanites get the blues too. Now we know.