The only thing tougher than singing for Simon Cowell? Keeping it together for the Pope. American Idol winner and pop star Kelly Clarkson proved she can handle both Saturday, performing "Ave Maria" for Pope Benedict XVI at Saint Joseph Seminary in New York in front of about 25,000.

"I was so excited to be asked to sing for the Pope," Clarkson said. "It's always been a dream of mine to perform 'Ave Maria.' To have that dream come true on such a special occasion is truly a blessing."

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