No, that was neither a jet taking off from the roof nor the sound of 1,000 squirrels sliding into a wood chipper Saturday night at the Marcus Amphitheater.

That was merely the sound we've all heard or read about in the last year that comes throughout a concert by Hanson, the sibling sensations who came in search of the "Man From Milwaukee" as part of its debut North American concert tour.

Still riding on the tsunami of their 10-million-plus selling 1997 album, "Middle of Nowhere," and the smash single "MMMBop," brothers Isaac (17), Taylor (15) and Zachary (12) kept the decibel level high during a set that ran from '60s vintage classic-rock to slick soul-pop of "Middle" and even a brief acoustic showcase drawing from the group's recent compilation, "Three Car Garage: The Independent Recordings '95-'96."

Hanson began with a quick run-through of the Spencer Davis Group's "Gimme Some Lovin' " meshed with the old R&B sing-along "Shake a Tailfeather." It only further teased the crowd, as many of its parents were still toddlers when those songs were hits.

The shrills grew sharper when keyboardist and lead singer Taylor broke into "Thinking of You," from "Middle," featuring silken verse like "I'm carrying this heavy load / I don't know what to do / The only thing I know / Is that I'm in love with you" (some high-school freshman!).

"Where's the Love?" evoked an even deeper swell of prepubescent swooning, with Taylor and company generating more soul than you'd ever, ever imagine possible from a trio of glowing and blond-hair flowing sons of a Tulsa-based oil executive.

By the time the three slowed things down on "Weird," the crowd took a few moments break from its squealing to sway their arms back and forth and mouth along to the way-deep lyrics, with a couple hundred or so illuminating the amphitheater with the flicker of Bics swiped from their parents.

Hanson is a good teen pop band. (Phew, there, I said it.) And what makes them so -- according to this humbly over-30 opinion -- is the voice of middling bro Taylor, whose bubble gum rasp has that elusive and treasured quality you'll find in most successful pop idols: distinction.

Love him, despise him or never know his name, his singing is neither great nor seasoned, but you'd recognize it anywhere.

It's a quality that came with the two lead singers of a pair of bands that Hanson's been endlessly compared to: The Osmond Brothers and the Jackson Five. In fact, if Michael Jackson dyed his hair blond, he might be able to pass as the "fourth Hanson."

But don't take the word of a creaking elder over a real expert: "I like all of them, but Taylor's my favorite," said Hanson fan Keali Zastrow, 8, who'll soon be strolling among the other third-graders at Eisenhower Elementary School in Wauwatosa. According to Keali's mom, Robin, Keali shrugged off Friday night aches, chills, a 102-degree fever and the sluggish effects of Children's Tylenol in order to attend.

Later, the brothers ran through a quick acoustic set featuring lesser-known material from "Three Car Garage."

They then headed into more tracks from "Middle," with each taking breaks to come to the stage front and empty their water bottles atop the adoring masses.