Summerfest was just the second stop on this year's "American Idol" tour, and the biggest surprise came in the first half of the nearly three-hour collection of individual performances.

The two youngest performers in the Marcus Amphitheater show, Katie Stevens and Aaron Kelly, both 17, offered sets that showed the promise of future stardom.

Stevens demonstrated a powerful voice and a rocker girl sensibility in two songs, Christina Aguilera's "Fighter," and Demi Lovato's "Here We Go Again." On the show, she demonstrated vocal talent, but an unsure stage presence.

Kelly, meanwhile, proved himself to be a marketable country artist, with a set list that included "Walking in Memphis," and "Fast Cars and Freedom." In his "Idol" run, Kelly seemed to offer a weak pop persona.

A quirky standout was Siobhan Magnus, whose combination of a unique fashion sense and singing came with a suitably dark take on "Paint it Black," that was familiar to "Idol" viewers. She also did No Doubt's "Spider Web."

The night's biggest names, of course, came at the end of a show that featured a number of empty seats. Lee DeWyze, this year's winner, and Crystal Bowersox, the silver medalist in the ninth season of Fox's singing competition, performed songs from the show.

DeWyze offered a more emotional presence than he did during much of his run for the "Idol" crown, belting out Leonard Cohen's "Hallelujah," a song that should be retired for a while to avoid burning it out. He also did an entertaining take on Elton John's "Rocket Man."

Bowersox also did familiar songs, like Melissa Etheridge's "Come to My Window" and Janis Joplin's "Piece of My Heart."

Neither the winner nor the runner-up surprised the audience. But then, these "Idol" tours are marketed to the young audience that votes, and every one of the 10 finalists offered their profuse thanks and expressed their love to the squealing fans.

There were no tightly choreographed group numbers as in some previous "Idol" live shows, although the bottom six finalists performed a song together, as did Michael "Big Mike" Lynche and Casey James.

There was only one number featuring the entire group, the evening's finale, with all 10 joining in on Kelly Clarkson's "My Life Would Suck Without You."

While the show unfolded with the characteristic precision of an "American Idol" production, the length of the show -- nearly three hours with intermission -- was visible in the tired younger members of the audience, many of whom stopped bopping about three-quarters through the evening's entertainment.