New York ? Simon’s back, and the knives are out.

“If you lived 2,000 years ago and sang like that, I think they would have stoned you,” judge Simon Cowell told one hapless contestant Tuesday on the return of Fox’s “American Idol.”

After the talent show became an unexpected TV hit last summer, Fox has brought back a second edition during the more competitive winter. The network isn’t shy about trying to ride the wave: Tuesday’s premiere stretched 90 minutes, followed by a half-hour update on first edition contestants.

Cowell, the sharp-tongued British record executive, was happy to slip back into his role as villain.

“This says you went to the Fame high school,” Cowell told one quivering contestant. “Did you get thrown out?

To a New Yorker: “I’ve heard better people sing outside of subway stations.”

To a Mariah Carey emulator: “Go back to your vocal coach and demand a refund.”

To an unfortunate soul who couldn’t grasp the reality of losing: “If you were to win and sing a song, you would kill the American record industry. That’s how bad you were.”

A few confident singers were brave enough to fight back. A handful of the rejected told Cowell where he could go. One said, cryptically: “At least I’m from a country where people brush their teeth twice a day.”

Besides Cowell’s barbs, the series’ strength may lie in the power and fragility of one’s dreams.

One 18-year-old singer, dressed in a garish yellow suit, oozed confidence during his audition and even argued with an unimpressed Cowell. After he was done, alone and hours from his home, tears streamed down the youngster’s face.

“You win some, you lose some,” he said. “Right?”