Source: Google Image
American Idol's Season 21 finale is happening on May 21 with a star-studded lineup of performers.
Source: Google Image
Keith Urban returns to the show as a mentor and will also perform on the finale night.
Source: Google Image
Judges Katy Perry, Lionel Richie, and Luke Bryan will each have their own performance on the finale.
Source: Google Image
The Top 12 contestants from this season will make a special appearance on the Idol stage.
Source: Google Image
Guest performers include Clay Aiken, Ruben Studdard, Ellie Goulding, James Blunt, and many more.
Source: Google Image
Katy Perry and Lionel Richie were absent from a previous episode due to performing at King Charles III's coronation.