Keith Urban will take a detour on his Escape Together World Tour this week to perform on 'American Idol.' The country superstar will sing on the finale of the reality competition show this Wednesday night.

"I think this year in particular has been one of the best for 'American Idol,'" says Keith, who told The Boot his wife Nicole Kidman got him hooked on the show. "There are some truly gifted vocalists ... What I love most about the show is watching the musical growth -- to see them use the critique given and come back the next week and blow you away. That's the magic of 'Idol.'"

Carrie Underwood will perform on 'Idol' this Tuesday night, singing 'Home Sweet Home' -- the Motley Crue song that the former 'Idol' winner re-recorded for use as the show's farewell song this season. Other artists scheduled to make guest appearances on the two-night finale include Lionel Richie, Carlos Santana, Cyndi Lauper, Queen Latifah, the Black Eyed Peas, and last season's 'Idol' winner, David Cook.