arts@sfbg.com

MUSIC Blues Control is an instrumental rock band, but don't hold that against them. The extended compositions and caterwauling guitars and keyboards may suggest post-rock bloat, but unlike many of their voiceless brethren, the duo knows that freedom is found in limits. Their crafty deployment of prerecorded loops and particularized live effects has etched a signature sound that's at once distinct and nostalgic. They're one of those mood ring groups that summons a whole lineage of avant-garde rock without exactly adhering to any one dominant influence. Pretty good, considering it started as a lark: needing an alter ego to protect their collaboration as Watersports from overexposure, Russ Waterhouse and Lea Cho fabricated Blues Control. Both projects were born under the sign of kosmische, but the newer songs refocused the drone zone with coaguutf8g tape loops and surprisingly friendly melodies. Hype soon followed.

If the duo's name comes off as an unfortunate nod to the many non-black blues units over the years (whether Breakers or Brothers, a Project or an Explosion), the smirk stops there. You can find any iteration of psych-rock in their origami structures, but Blues Control is always playing itself. When I talk with Waterhouse on the phone from Ithaca, N.Y., where he and Cho are on tour, he discusses his aversion to the hollow games of genre signification that were in vogue in the 1990s — a significant disclaimer, since their most recent release, Local Flavor (Siltbreeze), is their most ranging yet.

"The basic principles and methods of working have basically remained the same since the beginning," says Waterhouse, but Local Flavor benefits from new attention to texture and sequencing. The quartet of songs traverses carefully arranged prog-rock ("Good Morning"), Coltrane-colored mystical jazz ("Rest on Water"), a prismatic dance groove ("Tangier"), and a Bitches Brew-worthy cauldron of ethereal tones, dubby sidesteps and angry guitar ("On Through the Night").

These different encounters with psychedelia are nested within disarmingly crude nuclei of borrowed rhythms and spectral melodies. Throughout, the distinct processes of jamming and collage are placed in productive conversation. It's drug music without the inflated ego, a structuralist take on the basic rock furniture. When the core heats up, as on "Tangiers," Blues Control is close to perfect. Beginning with a breathy Casio loop, everything about the eight-minute track is percussive. A mashed, pulmonary beat hugs the centrifugal melody, while guitar and keyboard flares illuminate the elastic membrane stretching the song's surface. Halfway through, after several exuberant plateaus, the rhythm scatters into double and triple-timed graininess, and the Michael Rother-like vapor trails spiral into their own repeating figures. Moment-to-moment, the composition seems unchanging and mantra-like; skipping around reveals a remarkable, covert movement.

Not all of Local Flavor burns so bright. The horn-laden riffage concluding "Good Morning" is particularly Phishy, but it's a small misstep next to the dreamy gorgeousness of a track like "Paul's Winter Solstice," from last year's Christmas single for Sub Pop. I'll leave it to the historiographers to explain why so many of the most interesting interpretations of rock music have come from duos over the last decade, but Blues Control undoubtedly figures into the argument for a mobile, minimalist muse.

"With this tour, we're trying to follow through on some opportunities," Waterhouse explains.