Carrie Underwood is returning to "American Idol"

Why it matters: Underwood vaulted from "Idol" to superstardom after winning season four in 2005. She's been a darling of Music Row ever since.

• She is the first contestant ever to serve as a permanent member of the judges' panel. She'll join fellow country performer Luke Bryan and Lionel Richie.

The big picture: Underwood's "Idol" win was a seismic moment for the show and for country music. She became a titan of the genre at a time when women artists struggled to break through, and her powerhouse vocals set a new standard for Nashville stars.