Usher brought out Alicia Keys during his Super Bowl Halftime Show performance tonight (February 11) in Las Vegas.The 58th Super Bowl is taking place at the Allegiant Stadium tonight, with the San Francisco 49ers facing off against defending champions the Kansas City Chiefs.Keys appeared early on in the performance, taking to the stage first seated behind a red grand piano as a large piece of red fabric billowed behind her. She began by performing a clip of her own song ‘If I Ain’t Got You’ before Usher joined her to deliver a rendition of their 2004 collaboration ‘My Boo’.Throughout the set, Usher pulled largely from his album ‘Confessions’, which was also released in 2004 and from which ‘My Boo’ was taken.