The multi-platinum country artist shocked both the audience and Nalley when he joined mid-performance - pictures here.

During the Season 23 finale of 'American Idol,' Carrie Underwood performed 'I'm Gonna Love You' with finalist Slater Nalley, and Cody Johnson joined in as a surprise star guest.

As a former 'American Idol 'winner herself, Carrie Underwood has a special perspective on what words of wisdom a newly-crowned champ most needs to hear.

This was an unforgettable moment from the 'American Idol' finale (Carrie Underwood's first finale as a judge!).

This was the best reaction! Slater Nalley was performing with Carrie Underwood when a very special guest appeared.

John Foster went out with a bang during the Season 23 finale on Sunday night (May 18), treating the fans at home to a rousing ...

After a season filled with a slew of talent, the Season 23 winner of “American Idol” is Jamal Roberts. The newly-crowned ...

E! News catches up with 'American Idol' judge Carrie Underwood at the season finale. Plus, Jessica Simpson performs during the show and dishes on a possible tour.