SERIES FINALE: Fifteen seasons, and it comes down to this. As part of this two-hour last lap for American Idol, many previous winners and prominent also-rans are scheduled to return to perform live, including Carrie Underwood, Fantasia, Katharine McPhee, and Kelly Clarkson, who got very emotional when visiting, and singing, earlier this season. But then it’s time to crown the final idol – and last night, when finalists Trent Harmon and La’Porsha Renae sang for their votes, it turned out to be the closest Idol battle in years. I still think Renae will win, and deserves to, but Harmon’s encore performance of Sia’s “Chandelier” was so emotional, and so beautiful, he definitely could pull off an upset and win this thing. Either way, Idol is all but guaranteed to end the way it began, by discovering a singer who will make a big mark in the music business.