[STRIPPED-DOWN ROCK] Contemporary Portland rock acts seem to fall into two distinct camps: Groups that pile as many bodies as possible on the stage to create a maelstrom of sound and impact, and bands made up of two people. What's driving that split? Is it intentional or complete happenstance? 

For at least one duo—the groove-heavy rock outfit known as Bear & Moose—it is most definitely the latter. 

"We never set out to be a duo," says guitarist and vocalist Eric Mueller, taking a break from his family holiday craziness in Chicago. "We didn't decide that we were going to be this weird, White Stripes kind of thing. But if you don't have that certain connection with someone and it doesn't flow, why bother?"

Flow is the key factor that keeps the febrile attack of Bear & Moose so captivating and enticing on the band's two-disc debut, Bear/Moose. Mueller and drummer Simon Lucas have packed 24 tracks on the album, but it never feels cumbersome. 

The songs often bleed nicely into one another—the satisfying crunch of "Blues & Greys" giving way to the acidic swells of "I'm Back," which makes room for the appropriately punchy "Shock N Awe." Then there are the trio of tracks that wrap up the album, each bearing the title "MVMT." Those songs allow the pair to stretch their instrumental and improvisational limbs ("MVMT IV" was made up entirely on the fly) to capture what Mueller calls "the back-and-forth ebb and flow of a breakup.” 

The album also has an impressively full sound, capturing the duo's combination of bluesy swagger and the cumulus-scraping highs of psychedelia, considering the duo recorded almost all of it live in the studio. "We recorded [my guitar] through three amps at one time," Mueller says, "all of them turned up to 10 for this super-fuzzy Neil Young-type sound.” 

To make up for its lack of low end, the band's producer, Justin Phelps, added a second microphone to Lucas' kick drum and fed it through a bass amp in the studio. In live shows, Mueller adjusts his strumming style, sticking his thumb out to hit the lower-toned strings on the downstroke to add a basslike kick. 

With a sound this thick—and a debut record this good—Bear & Moose doesn't see any reason to spoil a winning formula. 

SEE IT: Bear & Moose plays Doug Fir Lounge, 830 E Burnside St., with Pigeons and Mike Coykendall on Thursday, Jan. 5. 9 pm. $8. 21+.