What transpired between those bookends, however, worked for everybody. The Decemberists, who named themselves after an early-19th-century Russian revolutionary sect (with the band adding an extra e to the name), have a well-deserved reputation for being brainy, bookish, and arcane - and proudly so.
Meloy is a native Montanan who prefers Olde English usages (note the straight-out-of-Sir Walter Scott spelling of chimbley) and drops references to Marcel Duchamp into his songs. He's an affable showman who jokingly chided front-row ticket holders for showing up late while "the people in the balcony were quite on time. If that's not an argument for a progressive tax, I don't know what is."
He assured people sitting in the middle of the 19th-century opera house that the gigantic chandelier hanging above them was certain to fall on their heads before the evening was through. And he habitually put extra syllables in his lyrics, using a word like motorcar, when plain old car would have done quite nicely, thank you very much.
All that, plus a predilection for a folkie strain of British prog-rock, makes the Stumptown quintet - which performed with multi-instrumentalist Sara Watkins filling in for Jenny Conlee, who was being treated for breast cancer ("Team Jenny" buttons were on sale in the lobby, all proceeds going to Susan G. Komen for the Cure) - too nerdy by half for some.
But by no means all: In January, when the band released The King Is Dead - its taut, catchy, and altogether winning sixth album that formed the backbone of its ingratiating set - the album topped the Billboard chart. And though it took some good-natured coaxing from the bearded, bespectacled Meloy, by the time the band got around to doing "Dracula's Daughter" (which Meloy proudly proclaimed to be "the worst song I ever wrote") in tandem with the soaring "O Valencia!", the singing-along crowd was on its feet and crowding the aisles.
Meloy took his taste for expansive Brit-folk concept rock to a logical extreme on 2009's The Hazards of Love, which was touched on effectively at the Academy with "The Rake's Song" and "Won't Want for Love (Margaret in the Taiga)."
But what made the punchy The King Is Dead so effective - and Wednesday night's show, too - was the way the band tightened up its songs and drew from Americana influences ranging from country music to R.E.M. ("Down by the Water" is a virtual rewrite of "The One I Love," and, in fact, R.E.M.'s Peter Buck plays on three songs on the album).
The more disciplined song structures highlighted Meloy's melodic talents, and the bracing appeal of his tart, not-for-everybody voice. With that sloppy all-hands-on-stage encore, the Decemberists couldn't resist stretching out till it all fell apart in the end. But for the most part, they were smart enough to do more with less.
Contact music critic Dan DeLuca at 215-854-5628 or firstname.lastname@example.org, or @delucadan on Twitter. Read his blog at www.philly.com/inthemix.