Visually, they look like members of the Czech Republic swimming team headed to an Olympic meet, with their matching shaved heads and track-suit jackets. Musically, they sound like a spaghetti western soundtrack for a modern shoot-'em-up movie, one filled with manic car chases set in a gritty, urban wasteland.

Artistically, the Blind Shake only seems to get better and better — which might be the most unusual thing about the incomparable power trio.

"We've never had huge success, but things just seem to keep progressing for us in cool, little ways," concurred Jim Blaha, one of the two brothers who play guitar in the decade-old band.

The latest sign of progress for Blaha, his younger brother Mike and drummer Dave Roper is a new deal with Castle Face Records, a San Francisco area label co-helmed by John Dwyer of the beloved experimental band Thee Oh Sees. Dwyer caught the Blind Shake's always-kicking, viscerally paced live show at a Pitchfork Music Fest after-party last year in Chicago, and at South by Southwest in March, where he wooed them for the label.

Castle Face will release the trio's latest album, "Key to a False Door," on Sept. 17, then the band will hit the road to play the garage-rock meet-up Goner Fest in Memphis and then open for Thee Oh Sees' fall tour. First, though, comes a hometown release party at the Turf Club on Saturday.

"We tried to be more melodic on this record," Jim said, which sounded like he was kidding. "At least by our standards," he added.

"Key to a False Door" indeed boasts more discernible song structures and stick-in-your-head lines than past Blind Shake records, which have included collaborations with Sub Pop-rediscovered '60s guitar-roar pioneer Michael Yonkers. But let's be clear: These guys are still about as far away from pop music as it gets, between Roper's jackhammering rhythms and the Blahas' furious, gut-punching guitar work.

As on the previous three full-length records, one of the keys to "False Door's" distinctive sound is the fact that there's no bassist in the band. Mike Blaha plays a baritone guitar — which falls halfway between a regular guitar and a bass in low-end sound. That's where the group's vaguely spaghetti western-ish sound comes from. The Blahas first got turned on to baritone guitars by the Am/Rep band Vaz (an offshoot of Hammerhead).

"The thing I don't like about bass parts is they're often not very subtle, like they're just too obviously setting up the chord changes for you," Mike Blaha said. However, here's the real reason the band doesn't feature a bassist: "Neither of us wanted to play bass."

Born on the East Side of St. Paul and raised in scenic Lake City, Minn. (birthplace of water-skiing!), the Blahas are one pair of rock 'n' roll siblings who actually get along. "We're pretty much each other's best friend," Jim even said.

Along with Roper, they've maintained day jobs while doing an impressive amount of touring in recent years. Mike also has a fledgling rehearsal-space studio, Banana Tone, where the band recorded half of the new record, while the other half was captured at the fancier Terrarium with Pony Trash's Neil Weir engineering.

"Sometimes a song needs that little extra depth that a real studio has to offer, and sometimes they just sound perfect caught on Mike's dirtier-sounding equipment," Jim said of the different settings. Noting one other distinguishing trait on the new record, he added, "We also used a lot more standard tunings on our guitars this time."

Wow, melodies and standard tunings? These guys really have sold out.

Random mix

St. Paul has taken the Sound Unseen film fest away from Minneapolis. Featuring all movies about music, the event will land again Nov. 13-17 with an expanded schedule between the Landmark Center, Summit Brewery, Amsterdam Bar & Hall and McNally Smith College of Music and just one Minneapolis site, the Trylon. … An obvious Sound Unseen candidate, the new documentary on Hüsker Dü's Grant Hart by "Color Me Obsessed" filmmaker Gorman Bechard will premiere at London's Raindance fest Oct. 6 and then show again a few nights later as part of New York's CBGB Festival. …

Next week at the Amsterdam Bar, 89.3 the Current is hosting another of its Public Music Meetings on Thursday (6-8 p.m.), offering listeners the chance to rate and see how music gets picked for the airwaves. … Fans of the Current's rockabilly darling JD McPherson should check out local newcomers Ross Kleiner & the Thrill, who take over Lee's Liquor Lounge on Saturday touting their impressive debut album, "You Don't Move Me" (9:45 p.m., $8). The Minneapolis-reared Kleiner has a cool Gene Vincent-style howl and one mighty backing band, anchored by sizzling Winnipeg guitarist Cornelius Watson. …

Pink Mink is back in action and ready to headline a cancer benefit for a friend at the Turf Club on Friday, also featuring the Seawhores and Still Pacific (10 p.m., $10.). … Acidic reggae/rap/rock wizards WookieFoot host another of their charitable Shangri-La festivals this weekend down in Harmony Park, with Keller Williams and dozens more (WookieFoot.com). … After a couple years of talking about it like it was their dirty secret, P.O.S. and Astronautalis debuted the first track from their duo act Four Fist this week. The song, "Mmmmmhmmmmm," and one other will be issued Oct. 7 as a limited-edition 7-inch single via Doomtree Records ahead of a full-length album in the works.

chrisr@startribune.com • 612-673-4658 • Twitter: ChrisRstrib