The title of Labradford's sixth and latest album, Fixed::Context (Kranky), is a bit misleading: since 1992, when Mark Nelson and Carter Brown formed the group in Richmond, Virginia, its personnel, instrumentation, and milieu have all changed. In its early days the band blended ringing guitars, whispered vocals, grinding tape loops, and thick analog synthesizer textures to create an ominous sound that couldn't have been more out of step with the straightforward guitar-bass-drums approach that dominated the D.C. area's musical underground--bands like Nation of Ulysses, Breadwinner, and Tsunami. But most of those outfits are history, and in the late 90s the vintage keyboard sounds that made Labradford's early albums so distinctive were beaten into the ground by a parade of space-rock pretenders. The group has also made some adjustments itself over the years: Brown has ditched his Moogs and Korgs in favor of pianos and organs, Nelson has quit singing, and bass guitarist and sampler player Robert Donne, who joined after the first album, 1993's Prazision LP, has impelled his bandmates to explore more rhythmic territory. Labradford embellished its previous three records with strings, but on Fixed::Context the band distills its once amorphous and sprawling music to its essence; the twangy, skeletal guitar melodies, solemn keyboard lines, and subliminal beats resonate in the vast empty spaces that surround them. At this show Labradford plans to play straight through the four spare, meditative pieces that make up the new album; with any luck, folks who feel like having conversations during the set will stay in the front room, away from the stage. Saturday, February 24, 10 PM, Schubas, 3159 N. Southport; 773-525-2508.