'American Idol' season 16, episode 12 recap and performances
American Idol/YouTube

"American Idol" completed its Top 24 round on Monday, having the dozen artists who performed during Sunday's show join forces with celebrity duet partners to earn the right to be "American Idol" season 16 finalists. At the end of the episode, judges Katy Perry, Lionel Richie and Luke Bryan eliminated five of the 12 to round out the Top 24. Whose performances impressed enough? Here are the highlights music fans need to know from Monday's episode:

1) Ada Vox's 'Wicked' cover

The highlight of the night was Ada Vox performing "Defying Gravity" from the Broadway musical "Wicked" with actress and singer Lea Michele. "Wicked" fans know that this song is very, very difficult to sing well; it's possibly one of the biggest, grandest songs ever written. Ada and Lea made it the showstopping number that it deserved to be; watch their performance by playing the video above. It's stupefying to think that Ada was rejected from "American Idol" when she previously auditioned as Adam, because now she has to be one of the frontrunners going into next week when America starts casting their votes.

2) Mara Justine's strong follow-up

Mara Justine had the best performance on Sunday night when she floored audiences with her version of "Run To You." What was she going to do for an encore? She chose another ballad on Monday, this time an inspirational one: "Fight Song" by Rachel Platten. Platten must have performed this song hundreds of times by now, considering that it's her biggest hit, but teaming up with Mara injected an energy into it that made it feel like the first time. The two clearly enjoyed sharing the stage together, and "Fight Song" was the perfect follow-up that allowed Mara to once again show off her vocal power.

3) Maddie Poppe gets 'Bubbly'

Not every number in a singing competition has to be massive. That's what Maddie Poppe and Colbie Caillat reminded us of Monday when they performed "Bubbly." Was it the most impressive performance of the night? No. Was it the biggest, in terms of the size of the performance and the stage presence? Nope. But it was good, clean fun and there's a place for that on reality TV, too. Maddie may have to step up her game to reach the heights of Mara and Ada, but she made it through to the Top 14 by giving us a duet that was simply entertaining.

"American Idol" airs Sundays and Mondays at 8 p.m. on ABC. Fans can get tickets to see judge Katy Perry live on her 2018 tour now through AXS by using the links below:

June 10 - Stockholm, Sweden - Ericsson Globe/Stockholm Live (Click here for tickets)
June 14 - London, England - The O2 (Click here for tickets)
June 15 - London, England - The O2 (Click here for tickets)
June 18 - Birmingham, England - Arena Birmingham (Click here for tickets)
June 19 - Sheffield, England - FlyDSA Arena (Click here for tickets)
June 21 - Liverpool, England - Echo Arena Liverpool (Click here for tickets)
June 22 - Manchester, England - Manchester Arena (Click here for tickets)
June 24 - Glasgow, Scotland - The SSE Hydro (Click here for tickets)
June 25 - Newcastle upon Tyne, Scotland - Metro Radio Arena (Click here for tickets)