It is the artists who weren't expected at California's Coachella Festival who have garnered the most attention this year.
Beyonce and Solange looked like they loved performing together
While enjoying scheduled appearances by acts such as Outkast and Muse, crowds at the huge site in Indio have also been treated to a number of surprise performances which have got them going wild.
Beyonce joined her sister Solange during her set for the song Losing You where the pair performed an energetic dance routine with beaming smiles on their faces.
Nas and Jay Z put their past feud behind them
Also not willing to just sit back and enjoy the festival atmosphere, Beyonce's husband Jay Z had earlier made a surprise appearance on stage with his former rival Nas.
Stefani and Pharrell sang Hollaback Girl together
Pharrell Williams enjoyed duets with a range of music stars including Puff Daddy, Busta Rhymes and Snoop Dogg but it was Gwen Stefani's guest appearance to sing Hollaback Girl which was most unexpected.
Justin Bieber wore dark glasses and a hat on stage
Fans whipped out their camera phones quickly when Justin Bieber suddenly appeared on stage with Chance the Rapper after teasing his fans with a Twitter post saying: "What am i up to today??
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Beyonce and Solange looked like they loved performing togetherWhile enjoying scheduled appearances by acts such as Outkast and Muse, crowds at the huge site in Indio have also been treated to a number of surprise performances which have got them going wild.
Beyonce joined her sister Solange during her set for the song Losing You where the pair performed an energetic dance routine with beaming smiles on their faces.
Nas and Jay Z put their past feud behind themAlso not willing to just sit back and enjoy the festival atmosphere, Beyonce's husband Jay Z had earlier made a surprise appearance on stage with his former rival Nas.
Stefani and Pharrell sang Hollaback Girl togetherPharrell Williams enjoyed duets with a range of music stars including Puff Daddy, Busta Rhymes and Snoop Dogg but it was Gwen Stefani's guest appearance to sing Hollaback Girl which was most unexpected.
Justin Bieber wore dark glasses and a hat on stageFans whipped out their camera phones quickly when Justin Bieber suddenly appeared on stage with Chance the Rapper after teasing his fans with a Twitter post saying: "What am i up to today??
"