There may be five years and several thousand miles between them, but Ben Monder's Excavation is the mirror image of Bright Side, the most recent album by Austrian guitarist Wolfgang Muthspiel.

It's a dark mirror, though, cracked and clouded. Both discs feature technically phenomenal musicians, each an adventurous improviser who gives equal weight to precisely arranged, often complex, through-composition—but while Muthspiel's aptly named Bright Side (2006) takes the listener down sunny, well lit paths, Excavation (2000, re-released) heads for edgier, more shadowy corners.

The album opens with the deceptively pretty "Mistral." Wave after wave of lush Monder arpeggios, fingerpicked Spanish guitar-style, roll out for over nine minutes. Vocalist Theo Bleckmann and drummer Jim Black enter on the second track, "Luteous Pangolin," when suggestions of darkness start to infuse the music.

While Excavation is no happy picnic in the park, it's never a downer. It has its downs, but also its ups, like life itself. The cornerstone tunes are "Ellenville" and "Hatchet Face" (like all but the final track, Monder originals). Each comes in at around fifteen minutes and is an unhurried exploration of atmosphere, developed through a succession of mini-movements, intelligent grooves, and freewheeling guitar improvisations mixing dextrous chordal passages and jetspeed single-note runs. "Hatchet Face" periodically lashes out with unmediated, grunge-like ferocity.

Monder's regular collaborators, Sverrisson and Black, provide empathetic support. But after Monder himself, it's Bleckmann's ethereal vocals—wordless on all but "Etching"—which are most key to the music and the vibe. You might hate most so-called jazz vocalists (and you wouldn't be alone), but Bleckmann stands a good chance of converting even the most hostile listener. His sensuous, pitch-perfect tenor magically enhances the atmosphere and mood.

The album ends with a three and a half minute version of the evergreen "You Are My Sunshine." If the Coen brothers were record producers, and Excavation was their take on bluegrass, this is how it might sound.

So welcome to the dark side. And when you feel like some sunlight, you could always check out Muthspiel's Bright Side—or read Monder's website biographies (there are two), which have some wonderfully self-mocking, funny moments.