The perfect phrase to describe the Black Eyed Peas is "boom boom pow," which is the title of their massive 2009 hit.

The Peas' music is simple, repetitious and explosive. Put the Grammy-grabbing, global pop sensations onstage in a high-tech, costume-fueled, futuristic setting and it added up Monday night to an eye-popping, bass-thumping, body-shaking party for an announced crowd of 14,000 at Xcel Energy Center.

The Los Angeles quartet succeeds with its high concept and lowest common denominator sounds. Think of the Peas as the ABBA of hip-hop, with irresistibly catchy music, simple sloganeering lyrics and feel-good vibes. Raise the mindless fun to the next level in concert by adding giant LED screens, enough lights to illuminate all of downtown St. Paul and an endless parade of outfits -- some robot specials, some smothered in sequins, some splicing leather and spikes, others swathed in chrome and plastic. Then send the four Peas skipping down the stage runway like glamour pusses and masked cyborgs on the yellow brick road.

But on the road to Oz in the Next Universe, the Peas could have used some heart, some emotion and some brains. Leader will.i.am knew how to pronounce "St. Paul" but stumbled on "Minne-an-apolis." Fergie could muster emotion on "Missing You," but she was cold as ice offering "Fergalicious." And the performances of hypemen Taboo and apl.de.ap were as mechanical as, well, the robotic dancers accompanying the Peas.

The solo detours for each of the Peas derailed the momentum of the two-hour show. apl rapping "Bebot" and "Mare" couldn't measure up to the excitement of Ludacris throwing down two verses with Fergie (wearing a silver porcupine outfit) on "Glamorous." Did anyone notice the song Taboo was rapping ("Rocking to the Beat") while he floated over the audience on a motorcycle with illuminated tires (a variation of a trick from Britney Spears' 2009 tour)? Because of her superstar solo career, Fergie's solo spotlight was mandatory, but will.i.am's DJ set (wearing a silver mask) spinning hits by Michael Jackson, Nirvana and Journey was an unnecessary 18-minute indulgence.

Thankfully, the quartet got back on track with two rare slices of social commentary -- the fist-pounding "Now Generation" about young people's preoccupation with cyberspace, and the peace-demanding "Where Is the Love?" -- and rocked out on "Pump It" and last year's record-setting smashes, the electronically pounding "Boom Boom Pow" and the unstoppably uplifting "I Gotta Feeling."

Those songs ring in your head like earworms, leading one to think that maybe, just maybe, 20 years from now, there could be a musical on Broadway called "Boom Boom Pow."

Opening were high-energy rapper Ludacris, who is riding high again with the hit "How Low" and the nation's No. 1 album "Battle of the Sexes," and the cartoon hip-hop duo LMFAO, who are Motown founder Berry Gordy's son and nephew.

For set list, go to www.startribune.com/artcetera

Jon Bream • 612-673-1719