Season 4's American Idol winner, Carrie Underwood, took the stage for a second time during the TV singing competition's series finale on Thursday night (April 7) to perform her hit "Something in the Water."

"Something in the Water" comes off of Underwood’s album Greatest Hits: Decade No. 1, which is available for download on iTunes and Amazon and became her fifth No. 1 album following its release. "Something in the Water" also reached No. 1.

“It’s really kind of a joyous, uplifting song about changing your life for the better and kind of having that ‘a-ha’ moment, to waking up and your life being different from that moment forward,” Underwood says of the tune.

Prior to singing "Something in the Water," Underwood teamed up with Idol judge Keith Urban to duet on “Stop Draggin’ My Heart Around.”

Underwood is currently out on the road on her Storyteller Tour, which she recently extended through November. In addition to the country superstar, the American Idol series finale included guest appearances by Kelly ClarksonScotty McCreeryBucky Covington, Casey James, Josh Gracin, Kellie Pickler and Lauren Alaina, as well as a host of other former competitors from throughout the show’s 15 seasons.

American Idol's Country Contestants: Where Are They Now?

Unforgettable American Idol Auditions

More From TheBoot