A pair of hardworking idols

No matter how big country stars get, they can never forget where they came from. Or, in Keith Urban's case, where his paycheck comes from.

After 16 years in Nashville, Urban's native Australian accent comes and goes. But despite the platinum records hanging on his wall, Urban still comports himself like a polite outsider.

As the clock neared 11 Friday night at Boardwalk Hall, Urban thanked the crowd for staying up late. "I know a lot of you have baby-sitters waiting at home," he said. "We're grateful for every person who's still with us at the end of the show."

He needn't have worried. Reports from Madison Square Garden had chunks of the crowd departing after the opening set from

American Idol

champion Carrie Underwood. But in Atlantic City, their fortunes were reversed: Underwood took the stage to a half-empty arena, but by the time Urban made his entrance, the place was packed, and stayed that way.

In deference to Underwood's fully risen star, her set was almost as long as Urban's: well over an hour, nearly all of it devoted to her new album,

Carnival Ride

.

Underwood's lung-busting high notes sent a wave of cheers through the crowd, but like most

Idol

contestants, she has yet to get a feel for a flesh-and-blood audience. Her limited vocabulary of half-waves and hand slaps was mechanically deployed, and her patter felt as if it had been concocted by writers waiting in the wings.

When she donned a ball gown with a gauzy train and stood atop a lit-up platform, she looked less like a small-town girl than Glinda, the good witch.

Urban, by contrast, couldn't get enough of the crowd. The dominant feature of his stage set is an enormous high-definition screen big enough to let viewers in the cheap seats count the hairs in his beard.

His give-'em-what-they-want set, drawn almost entirely from his new greatest-hits collection, was interrupted by thank-you's and a brief but credible sing-along of "Blister in the Sun."

After the encores, Urban spent several minutes on the catwalk shaking hands. The show was over, but he wasn't yet ready to leave.