There never has been much of a question that the New Pornographers are a cerebral power pop band -- A.C.

Newman's songs dance around meaning and Dan Bejar deliberately turns meaning inside out -- but they always hit the gut instead of the head due to their propulsive melodies and sweetly muscular guitars.

Such was the case up through 2005's Twin Cinema, anyway, but on their fourth album, 2007's Challengers, they turn inward, tempering their hooks and muting their colors, winding up with an album that emphasizes their admirable qualities first, with their endearing ones revealing themselves only after repeated plays.

It's true that the New Pornographers' albums have always been growers, records that unveiled their gifts over time, but Challengers is their biggest grower yet, a dense collection of carefully constructed and brain-power pop where even the liveliest song, "All the Things That Go to Make Heaven and Earth," is a tense, nervous cacophony of ideas and riffs that doesn't grab hold -- it plants a seed that later blooms.

Few of the other songs here are as fast or jumbled as that -- it's every bit the early Roxy Music salute Newman claims it is -- as the rest of the album dwells over slower, softer territory, or precisely written pop tunes where no left turn goes unexplored.

At least that's true of Newman's tunes, and he once again dominates the album, writing nine out of the 12 tracks.

Newman has a knack for writing segments that are bright, hooky, and seemingly indelible, possessing the blinding rush of the best power pop, but when he's writing for this band, he assembles these colorful shards of melody in challenging ways, creating intricate mosaics where the melodies never quite lead exactly where they seem they would.

Although the New Pornographers play these songs with an unassuming directness, Newman's pop requires active listening, especially here on Challengers, as it's built upon carefully arranged and quietly performed songs.

Bejar balances these precious tendencies of Newman by indulging in his eccentricities.

His songs aren't as detailed in their arrangements, but this only accentuates his oddness, where he can make either the slow, spooky crawl of "Myriad Harbour" or the delicate Brit-pop stomp of "Entering White Cecilia" seem equally off balance.

As always, this does make for a good contrast to the essential sweetness of Newman's melodies (perhaps best heard on the openers, "My Rights Versus Yours" and "All the Old Showstoppers," the gateway drugs for the rest of the album), but it often seems as if Newman knows that he has a gift for these sweet melodies, so he undercuts that gift by having his melodies follow unconventional paths, and by having his lyrical meaning so well hidden that it often seems not worth the bother to analyze.

So, this is internal music, best suited for solitary listening, but the odd thing about Challengers is that it has the inherent tension and messiness of a band, where harmonies float in and out and the group rides a natural rhythm instead of a click track.

And that, more so than the seesaw between Newman's and Bejar's songs, is the true balance of the New Pornographers, because both writers benefit from having a band that plays like a band: while you may not be able to decipher these writers immediately, they sell their eccentricities as something that's quintessentially, endearingly human, and that talent proves invaluable on a record as subtle, yet rewarding, as Challengers.