American Idol had a few tricks up its sleeve last night, March 24, as the remaining contestants battled it out with Motown classics. 

Musical icon Stevie Wonder took to the stage to perform 'Signed, Sealed, Delivered I'm Yours' and as he finished belting out the classic track, he called on judge Steven Tyler for a personal surprise. 

Speaking out to the Aerosmith frontman, Wonder asked:

"Steven! Steven! Steven Tyler! How are you doing? Are you ready for a celebration? Are you ready for it? You know this is what friends do for friends, and I feel like this is something you don't know about! Can we hit it?"

He launched into his own version of 'Happy Birthday' to celebrate Tyler's 63rd birthday, which is tomorrow, March 26, and the cast and competition's finalists presented him with a cake and a painted canvas. Watch the clip here: