'American Idol' Recap: Farewell Season Finalists Sing One Last Time for America's Vote
"That one just sort of fell by the wayside a little bit," Urban said of the song. "I was focusing on the songs and the next thing I knew they called me and asked if I would be cool with Trent singing it. I was all for it."
And what did Urban think of Harmon's performance? "I heard his version of it and it was amazing," he said.
As for Thursday night's finale, Urban said he will perform a "cover" with a mystery guest. "I am doing a song everybody knows with someone that I toured with years ago," he hinted. "We used to do this song together. It is going to be fun."
Urban said America has a tough choice to make between Harmon and La'Porsha Renae for who will be the last American Idol.
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"Both had moments when their abilities were perfectly matched and really played to their strengths," he said. "La’Porsha is a phenomenal singer so there was never a question that she was going to be here. I thought it was all hers until Trent came out and sang and I thought this is a really close race."
Urban's new album, Ripcord, drops on May 6. His tour kicks off in Kansas City on June 2.