Alicia Keys & Kendrick Lamar perform 'Its On Again' on Fallon...

Promotion for ‘The Amazing Spiderman 2.′

Alicia Keys and Kendrick Lamar dropped by The Tonight Show With Jimmy Fallon to deliver the first live performance of their Pharrell produced single ‘Its On Again’. Alicia donned a modern mullet, leather jacket, black jeans and heels for the performance. The mics of her background singers' were turned all the way up but at least the performance was rocking.

The track appears on the soundtrack of the upcoming movie ‘The Amazing Spiderman 2′, which opens in theaters on May 2nd. Check out the performance below.