'DWTS': Three couples remain, but only one can take home gold Mirrorball trophy

Two-part finale of "Dancing with the Stars"

After weeks of competitive dancing, the three remaining couples advance to the final of "Dancing with the Stars" tonight (8-9:01 p.m. ET). Noah Galloway and Sharna Burgess, Riker Lynch and Allison Holker, and Rumer Willis and Valentin Chmerkovskiy have one last night as they vie to win the judges and America's votes to be crowned the season 20 "Dancing with the Stars" Champion Tuesday (9-11 p.m., ET) on the ABC Television Network.

On Monday, the three finalists will compete in two rounds of dance. In the first round, each couple will repeat a dance from earlier this season. In the second round, in one of the biggest competitive dances of the season, the couples take on a supersized freestyle dance featuring special effects, additional dancers and unexpected surprises.

In the two-hour season finale Tuesday, the show kicks off with a high-energy opening number featuring a reunion of all 12 of this season's couples, in addition to the judges and hosts. Then, one couple will perform an encore of its freestyle dance as decided on by the judges.

The finale will also feature a performance to "Juicy Wiggle," by RedFoo and encore performances by Charlotte McKinney and Keo Motsepe to "California Girls"; Suzanne Somers and Tony Dovolani to "Copacabana," featuring six additional dancers; Robert Herjavec and Kym Johnson to "Bills"; Chris Soules and Witney Carson to "Footloose"; Willow Shields and Mark Ballas to "Alice's Theme"; Nastia Liukin and Derek Hough's Charleston to "Honey, I'm Good," featuring a performance by Andy Grammar and much more.

The night will also include a reprise performance from Patti LaBelle and Artem Chigvintsev to "In Da Club," and the Grammy-winning artist will also perform her hit song "2 Steps Away." Additionally, fan favorites from past seasons Amy Purdy, Alfonso Ribeiro and Sadie Robertson return to the ballroom for special performances.

Sia will perform her hit song "Elastic Heart" with a special dance performance by Derek and Julianne Hough. The star-studded night will continue with a performance by Jason Derulo singing his song "Want To Want Me." In the last element of competition, the couples will perform a new routine as part of a "24 Hour Fusion Challenge." The remaining couples will fuse two contrasting dance styles they've performed this season and they'll have less than 24 hours to prepare that dance for additional judges' points.

At the end of the night, the winner of the gold Mirrorball trophy will be announced.

Viewers may cast their votes for their favorite teams via phone Monday night during and up to 60 minutes after the end of the "Dancing with the Stars" broadcast in each time zone. Online voting at www.ABC.com and on Facebook at https://apps.facebook.com/votedwts/ is open for 15 hours, beginning from the start of the episode Monday on the East Coast at 8 p.m. and closing at 11 a.m. Tuesday.