So this is how far we've come? In 1958 a little chipmunk named Alvin shocked the country by selling 4 million copies of "The Chipmunk Song." Well, that was nothing compared with what happened at the Patriot Center last night.

Live onstage were four giant turtles (class reptilia, order testudines, suborder cryptodira; family and genus could not be readily determined, although the vertebral, pleural and marginal horny scutes visible on the guitarists' carapace suggested emydidae and terrapene, respectively) playing rock-and-roll with a giant rat! They were young (teenage), genetically messed up a bit (mutated) and well trained in martial arts (certified as ninjas by Splinter, the aforementioned rat).

Okay, I know what you're thinking: We've had animal groups in the past, including the Monkees. But they were nothing compared with the hard-shell rockers who jammed last night.

How many groups can play difficult rock guitar solos (with only three fingers, no less!) and at the same time fight off Shredder, the evil silver Samurai who had followed the Teenage Mutant Ninja Turtles on this tour with his diabolical De-Harmonic Convergence Converter?

The TMNTs rapped, they rocked, they rolled, they danced and they taught lessons on fighting for what you believe in. And judging by the screams coming from the large crowd (the empty seats were deceptive -- many of the audience members had crawled up into Mom's and Dad's laps to get a better view), the band has a promising live performance career ahead to match its success in comic books, television, film and records. It was a bodacious time for all and at only $9.50 to $14.50 a ticket, a real bargain.

The TMNTs made a grand entrance, rising out of sewer holes in a set designed to look like an urban street, but they played only a few songs before that pesky Shredder-dude appeared. He interrupted the concert with threats to suck all the music out of the world with the De-Harmonic Convergence Converter. That didn't faze lead guitarist Michaelangelo. He told the audience that evil people like Shredder could be avoided if everyone would just "be cool, be yourself." With that, the group whipped into "Walk Straight," a galloping rocker in the big-guitar tradition of Bon Jovi. But it wasn't all raucous hard-rock stuff: The TMNTs were versatile, rapping on one song ("Cowabunga") and even singing a cappella for "Follow Your Heart."

But the group really didn't hit its musical peak until Shredder took away the lovely April O'Neil's voice as part of his no-music plan. The red-headed television reporter, a favorite among the dads in the audience, could only regain her voice through really heartfelt music. And she got it. With bassist Leonardo, percussionist Raphael and keyboardist Donatello singing harmonies, Michaelangelo kicked out a John Cougaresque roots rocker called "You Can Count on Us," which restored O'Neil's vocal abilities. And when she sang again, all the world seemed just and right.

Apparently aware of the lip-sync facade surrounding many of today's pop groups, several audience members questioned whether those green guys onstage were really the TMNTs. "Are those costumes?" asked 3-year-old Angelica Spanos of Falls Church, of no one in particular. "Those are just costumes," answered her 6-year-old brother, John. "They made them some place." Angelica looked as though someone had just told her Santa Claus didn't exist.

Like every big concert, there was plenty of action offstage too. The security staff at this concert had a heck of a time keeping the audience members from climbing on the railings during intermission. A flustered usher named Ann gingerly picked one girl off and put her on the ground. "Honey, I told you to either go up in the seats or stay down," she said gently. Then, addressing the nearby crowd, "I just don't want to see little heads on the ground." Yuck. Sounds like a punk show.

Things were no calmer at the merchandise stands in the hallways. Mother to son after purchasing a set of plastic nunchuks: "Keep it in the bag until we get home!" There were also TMNT sweat shirts ($28), T-shirts ($14 and $16), programs ($10), vests ($10), three different plastic swords ($8), painter's hats ($7), dolls ($6 and $7), masks ($6), cutouts ($5), light wands ($5) and buttons ($5 and $3). There was even cotton candy that was tinted -- you guessed it -- green.

Ah, the color of money.

The TMNTs are performing through Sunday at the Patriot Center to support their debut record "Coming Out of Their Shells."