The 'American Idol' finale celebrated the conclusion of its 13th season by inviting big stars onto its stage to perform alongside the former contestants and two finalists. Check out performances by Demi Lovato, Paramore, Phillip Phillips and more.

Jennifer Nettles, 'That Girl' and 'Wrecking Ball'

Jennifer Nettles started off the show dressed in a loose white blouse and rose-embroidered pants, singing her hit 'That Girl.' The country star was then joined by contestant Jessica Meuse to duet a beautiful rendition of 'Wrecking Ball.'

Phillip Phillips, 'Raging Fire'

Phillip Phillips’ set was kicked off by 'Idol' contestant Sam Woolf, who made it through most of 'Home' before the song's original singer grabbed a guitar to join in for 'Raging Fire.' Phillip looked at home on stage with his acoustic guitar and leather jacket, red lights flashing behind him.

Jennifer Lopez, 'First Love'

WOW is the best way to sum up Jennifer Lopez’s 'First Love.' From her sexy fishnet-and-fringe leotard, to her seductive dance moves, to the sheer energy that she had moving and jumping around on stage (she even ended up on top of the judges' table), it's obvious that even now she's still Jenny from the block --- fitting, since that's what she ended her performance with!

Kiss, 'Love Gun' and 'Shout It Out Loud'

One of the two finalists, Caleb Johnson fulfilled the dream of a lifetime by performing with Kiss. The band was decked out in classic Kiss gear, including platform shoes and full-face makeup, of course. If Caleb hadn't won 'American Idol,' we might suggest he ask Gene Simmons for a spot in the group. His voice fit in perfectly!

Aloe Blacc, 'The Man'

Aloe Blacc was looking fresh in a purple velvet blazer as he sang his R&B hit 'The Man.' He was joined by all of this season's guy contestants, each of them taking a few lines of the verses. Aloe's performance was a judge favorite --- they all knew the words and were singing along.

Demi Lovato, 'Really Don't Care' and 'Neon Lights'

Demi Lovato looked too cool in her glittery leather jacket, jumping around and belting out her latest single 'Really Don't Care.' She then shared the spotlight with all of the girl contestants from this season, who joined her on stage to help perform her hit 'Neon Lights.'

Paramore, 'Ain't It Fun'

The second 'Idol' finalist, Jena Irene, also got to perform with one of her favorites. She started off in front of a piano singing a Paramore classic, 'Decode.' The slow song transitioned into the upbeat tune of 'Ain't It Fun' when the band appeared on stage and used Jena's help to perform their latest single.

John Legend, 'You and I' and 'All of Me'

John Legend is an amazing singer and an amazing piano player, as seen in tonight's performance of 'You and I.' Afterwards he was joined by contestant Malaya Watson for a duet of 'All of Me.' The song is gorgeous as-is, but it was brought to another level when presented as a duet.

Jason Mraz, 'Love Someone'

Jason Mraz is back! He performed his first single 'Love Someone' from his upcoming album 'Yes!', due out later this summer. 'Idol' contestant Alex Preston stood alongside him as the second guitarist (Jason being the first), and to share a few verses with the 'I'm Yours' singer.

Richard Marx, 'Right Here Waiting'

Randy Jackson started off this funny segment explaining that he's been trying to get 'American Idol' host Ryan Seacrest to perform all season. His persistence paid off --- Ryan began a wobbly, out-of-tune version of Richard Marx's famed song 'Right Here Waiting.' Luckily for Ryan, and us, Richard was actually there to take over.

Darius Rucker, 'True Believers' and 'Alright'

Darius Rucker showed off his country twang with a bit of 'True Believers,' from his latest album of the same name. AI contestants CJ Harris and Dexter Roberts, each equipped with a guitar, joined the star to perform Darius' old hit 'Alright.' (Keith Urban is a big fan, apparently --- he was up out of his seat and mouthing along to every word.)

Lady Antebellum, 'Bartender'

The two 'American Idol' finalists, Caleb and Jena, introduced the next band by singing a few lines from Lady Antebellum’s smash hit 'Need You Now.' The country trio rocked the stage in the premiere of their latest single 'Bartender,' sounding as great as ever during their new sultry break-up song.

Randy Jackson, Harry Connick, Jr., Keith Urban and Jennifer Lopez, 'True Colors' and 'Go Your Own Way'

Ex-judge Randy Jackson and current judges Harry Connick, Jr., Keith Urban and Jennifer Lopez banded together to give the final performance of the night. JLo kicked off the vocals for a cover of Cyndi Lauper’s 'True Colors,' with Randy on bass, Harry on piano and Keith on guitar. They looked like a real band in the making! To end things on a fast-paced high note, they took on --- and smashed --- Fleetwood Mac’s 'Go Your Own Way.'

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