Stevie WonderWe're not sure what changed in 'American Idol,' but they actually managed to make their usually bloated results show must-see TV this week. From the beginning to the surprise ending, it was compelling edge-of-your-seat stuff.

In the spirit of Motown, the first treat came during the group number. After it wrapped, the contestants lined up on either side of the big screen behind the stage, which opened to reveal Motown legend Stevie Wonder.

After his performance, he surprised Steven Tyler by calling him out and then breaking out into his version of 'Happy Birthday.' The contestants revealed a cake and a trippy painting of the Aerosmith frontman to honor him. Watch the video below.