American Idol's season final performances by the Top 2 will go down on Wednesday.

Kree Harrison and Candice Glover will go head to head to earn the most votes to win this year's American Idol title. The winner however will not be announced until the results show on Thursday.

Harrison and Glover will perform three songs each, according to American Idol Fandom.com. One will be a pick from the show's creator, Simon Fuller, the second will be the favorite song that they performed earlier in the season and the third pick will be a "coronation song" that will likely be an original single they will release if they win.

Tonight's final performance will offer at least one guest musical performance. Call me Maybe singer Carly Rae Jepsen has been confirmed to appear on Wednesday to sing her new song, Take A Picture.

Thursday's live finale is rumored to feature pre-taped segments by Idol judges Keith Urban and Mariah Carey.

Season 10 and 11 judge Jennifer Lopez is also rumored to perform her new single, Live It Up tomorrow and and Gangnam Style rapper Psy is also rumored to be making an appearance.

Season 12 winner Philip Phillips and former Idol Adam Lambert, as well as Angie Miller - this season's third place eliminated on May 9- will likely join the lineup. The Band Perry may also perform with 5th place finisher Janelle Arthur.

Fans of the show can vote for their favorite contestant when the voting window opens after Wednesday's performances. They will be able to cast their ballot for at least two hours.

There are four ways to vote for the contestant.

CALL: A toll-free number that will pop up on the television screen during Wednesday's performance and on a cellphone by text.

TEXT: Simply text the word 'VOTE' to the four-digit code that appears on the screen during the Idol performance.

ONLINE: Visit AmercicanIdol.com. For the first time ever, a fan can submit up to 50 votes per Facebook account

APP: Your selection can also be made on your mobile phone by casting your ballot on the American Idol App which is available on the Android and iOS device (handheld or tablet) with your Facebook account.

American Idol's Top 2 final performance show will air on Wednesday, May 15 at 8/7c and the season 12 finale will air on Thursday, May 16 at 8/7c on FOX.

Tags: American Idol