Jacket isn't a perfect fit for the Pops

"I have a feeling there are two groups of people here tonight," mused conductor Keith Lockhart at the start of last night's Pops on the Edge concert featuring the Kentucky band My Morning Jacket. That was an understatement. Up in the first balcony: a cluster of coiffed seniors, the unsuspecting season ticket holders, who politely endured howling and fuzz previously unheard in these hallowed halls. The rest of the place was packed with young fans shouting song titles and declaring love for the wild-haired rockers in tuxedos.

If the task was to lure a new generation to Symphony Hall: mission accomplished. But if measuring the success of the Pops-My Morning Jacket collaboration involves art and aesthetics, the end result was less certain. Moments of real drama were few, and the peaks were thrilling enough to make us wonder why more of them weren't built into a set that often reached for a middle ground rather than embracing juxtapositions. When frontman Jim James dropped to his knees and began to screech while scores of string players carved filigreed patterns -- that was a marvel. It was also the moment that prompted James to declare the night ``a surreal dream."

But much of the show -- which featured such midtempo cuts as ``At Dawn," ``Gideon," ``Golden," and ``Wordless Chorus" -- felt overly muted. It was as if the band reined in its haunted, sprawling sound to make space for the orchestra and the orchestra held back so as not to step on the rock heroes' toes, everyone politely avoiding the very collisions that make such an endeavor interesting.

Patrick Hallahan played an electronic drum kit, and on ``The Way That He Sings," especially, one craved the snap of a snare. (To be fair, I accused the drummer in Guster, last season's maiden Pops on the Edge guests, of eating the flutes alive.) But toward the end of the MMJ song, when the electric guitar and the brass section cranked in a wooly duet, the sound of hands clapping in time was a clue to what was missing.

Ironically, the first half of the program was more provocative and eclectic than the symphonic rock set. Bjork's bittersweet ``Overture," Christopher Rouse's frantic ``Bump," an excerpt from Elvis Costello's buoyant, dark-hearted ``Il Sogno," and Gershwin's ``An American in Paris" made an edgy mash of whimsy and sophistication.

Joan Anderman can be reached at anderman@globe.com