Jennifer Lopez joined Taylor Swift on stage to sing a special rendition of 'Jenny From the Block'. Swift was in Los Angeles performing at the Staples Centre on her Red Tour when Lopez joined her on stage. Swift announced Lopez's entry by asking the crowd "So I'm just wondering, Los Angeles, how would you feel if there was a special surprise guest?" Lopez's performance marked the end of Swift's four night run in Los Angeles.

Taylor Swift
Taylor Swift performing at the Staples Center, L.A. on her Red Tour.

Swift described her Los Angeles audience as an "incredible, amazing, wonder, unforgettable crowd." She then hyped up the unsuspecting audience by asking them "now I don't know about you, but when I was little, you know you had that favourite song? That you used to play over and over and over again? Just blast it in your room. And you'd sing in front of your mirror into a hairbrush, right? And you had that one favourite song. Los Angeles," Taylor announced "this is my hairbrush song." Lopez appeared on stage, in a highly rehearsed performance, wearing a sparkling white outfit which complimented Swift's black sequined shorts. 

Watch Taylor Swift and Jennifer Lopez perform 'Jenny From the Block':

Lopez is not the only singer to have performed on Swift's Red Tour. Amongst those who have appeared - so far- are Ellie Goulding, Tegan and Sara, Sara Bareille and Cheryl Lloyd. Swift is on the final leg of her Red tour, she will be ending her tour in Nashville, Tennessee where she will play the Bridgestone Arena for three nights. 

Jennifer Lopez
Jennifer Lopez performing in London's Hyde Park.

Taylor Swift
Taylor Swift performing in Chicago on her Red Tour.