As Hannah Montana, or Miley Cyrus, teen excites her legion of fans

That wasn't just the usual noise of jets taking off at O'Hare early Saturday evening. That was the sound of thousands of preteen girls shrieking at the start and finish of every Hannah Montana song at the Allstate Arena.

Montana is the alter ego of Miley Cyrus from her Disney Channel TV series of the same name, and the two of them did a split-set concert before a sold-out house at the Allstate. Camera phones flashed, girls screamed and, egged on by an office-supply store handing out posters customized with markers, they shook placards reading "I (heart) U Hannah." But "The Best of Both Worlds" show was hardly a case of split personality. The differences between the first and second halves of the 19-song, 90-minute concert were subtle, and in the end the impression Cyrus made was of a natural performer comfortable onstage.

With the help of a couple of background singers, Cyrus appears to do her own singing, no lip-syncing, and why not? Her bouncy pop is refreshing mainly as a reaction against the cheap melisma encouraged by "American Idol," and nothing she does is too demanding. The same goes for her choreography. Although augmented by a dance crew, she mostly flits and skips around the stage while staying on the beat (something Britney Spears, to name one former teen idol, always had trouble with).

Whether as Hannah or herself, Cyrus seems at ease as an entertainer in front of her sinewy five-piece backing band, and her fans -- and their parents -- can sense that. It makes the show enjoyable, and the composure is pretty impressive for a 15-year-old, even the daughter of Billy Ray Cyrus.

"The Best of Both Worlds" Tour probably could have filled the Allstate Arena for a week, but it was intentionally kept short so as not to be too grueling.

If that created a scalper's market, with as much as $4,500 being asked for a single seat online, don't blame Cyrus. The top ticket price was $66, and a dollar from each ticket went to the charity City of Hope.

Descending to the stage in a pink box, Montana opened the show with "Rock Star." Everything she wore sparkled, even when she went through the first of six wardrobe changes for "Old Blue Jeans."

"Even her jeans are sparkly," said my 11-year-old daughter, Meg.

Yet when she did "Nobody's Perfect," and almost every girl in the crowd seemed to sing along, it was a heartening sentiment, given how much of pop culture holds girls to an impossibly perfect standard of body image and behavior.

The Jonas Brothers, who were also the opening act, joined her for "We Got the Party," then did a two-song interlude while she switched to Miley Cyrus, re-emerging in a leather biker vest and sparkly biker chain for "Start all Over." But for abandoning the straight blond wig for her own tawny brown mane, there wasn't a whole lot of difference between the two sets. If Cyrus' half of the show seemed to plod a little by comparison without the upbeat party songs, she could still pull out "G.N.O. (Girls' Night Out)" toward the end, then finished with "The Best of Both Worlds," singing alongside an image of her Hannah Montana character on a huge stage screen.

For the encore, however, she wore a distinctly unsparkly sleeveless T-shirt and jeans, and sat on a stool and accompanied herself on guitar on "I Miss You," allowing a little natural country twang to creep into her voice. It wound up being my daughter's favorite song of the night, and I think that says something for the future of Miley Cyrus -- as a singer and as her own person.