Thursday night's season finale of "American Idol" was packed with talent. Judge Mariah Carey took the stage to perform a medley of her greatest hits including "Vision of Love," "Make It Happen," "My All," "Hero," "We Belong Together" and her new single "#Beautiful."

Fans cheered as she effortlessly belted away but others speculated that the singer's flawless performance was lip-synched. Carey and her reps are insisting that the singer's performance was live.

"ET can set the record straight as Mariah's reps tell us she absolutely sang the entire medley ... completely live," "Entertainment Tonight" reported.

Her rep also added that not only did she sing live, but Carey entertained the audience with additional songs in between live shots.

Another "Idol" judge, Randy Jackson, was on stage playing bass during her performance. It was recently reported that Carey had dropped Jackson as her manager, but it was an amicable split.

Other "Idol" performances included ex-judge Jennifer Lopez, who performed her new single "Live It Up" with Pitbull. "Gangnam Style" singer Psy dazzled the stage, as well as, season eight runner-up Adam Lambert and panel judge Keith Urban.

Probably the most impressive "Idol" performance was with winner Candice Glover and former "Idol" contestant Jennifer Hudson. The two took the stage and performed a duet of "Inseparable." Candice started the duet off sounding flawless and then introduced Hudson. Candice had no problem keeping up with the superstar and both shined on stage.