CORRECTION: An earlier version of this report misstated contestant Caleb Johnson’s last name on first reference.

Wednesday night, American Idol reached Episode No. 500. The show pulled out all sorts of stops to celebrate, even bringing out a cake at the end. Winners from across the show’s 13 seasons sent in video shout-outs, and The Chainsmokers started off the show so everybody could take a #Selfie.

The show had plenty of late-season plot twists, too. Alex Preston was sick over the weekend, but Caleb Johnson had all but lost his voice at showtime. The producers brought out the show’s physician, Dr. Shaun Nasseri, to explain that Johnson was suffering from bronchitis and sinusitis and had a minor vocal-cord hemorrhage. “He’s like a runner who’s running with a badly bruised ankle, but I think he’s going to do fantastic.” Ryan Seacrest kept his banter with Johnson to a minimum, at one point letting him answer questions by writing on sheets of posterboard.

The night broke down into three rounds: One new song picked by mentor Randy Jackson, one new one by the judges and one early-season favorite selected by the hometown fans.

Seacrest also announced the first pairings for next week’s finale show, which will take place Wednesday (the performance showdown will air Tuesday). They include: C.J. Harris and Darius Rucker, Jessica Meuse and Jennifer Nettles, Malaya Watson and John Legend, Sam Woolf and Phillip Phillips and Demi Lovato with the female finalists.

As far as the performances, Preston probably won the night, with Irene finishing strong. But one big question remains: How much sympathy vote will Johnson get?

RANDY JACKSON’S CHOICE

Caleb Johnson, Never Tear Us Apart (INXS)

Jackson said he wanted to give Johnson something that would help him sound contemporary and hint at the kind of artist he could become. So he goes with a 27-year-old INXS tune, which does take Johnson outside his usual stylistic choices. “It gives you a chance to be bluesy,” Jackson tells him. “It gives you a chance to show your voice and be range-y.”

Johnson begins the song sitting in a throne-like high-back chair, and he struggles a bit at the upper end of his range. But if Seacrest hadn’t said anything at the top of the show, few people would have noticed. He’s a pro, that’s for sure.

Keith Urban tells Jackson he made a great call. “I could hear the voice in certain spots, but you’re such a pro, you worked right through it.”

“You on your worst night are better than people on their best night,” Jennifer Lopez says, adding that she wants Johnson to pace himself. Harry Connick Jr. liked Jackson’s choice because it made him work within confines. He’s mostly concerned that Johnson not hurt himself tonight. Grade: B+

Alex Preston, Pompeii (Bastille)

Jackson considered Jeff Buckley and Calvin Harris before settling on Bastille’s current hit. “I think it’s modern, and I think, in an uptempo way, this is the kind of band song you might…