Solange's set at a Coachella on warm Saturday evening in Indio, California was punctuated by the most impressive of cameos - when her big sister Beyonce made an appearance on stage.

Beyonce - who was not advertised, nor tipped, to appear - joined her sister for a performance of 'Losing You', along with a pretty epic dance routine to boot.

In another surprise appearance, teenage heartthrob and occasional delinquent from justice Justin Bieber joined his pal Chance The Rapper while he performed his section from James Blake's 'Life Round Here', after which the duo launched into a segment of their collaboration 'Confident'.

Elsewhere, Pharrell Williams was joined during his set by Snoop Dogg, Nelly, P Diddy, Gwen Stefani, Tyler The Creator, Diplo and Busta Rhymes where he performed snippets from his collaborations with what seemed like half the Coachella bill, even if his performance of 'Happy' was slightly muted by an occasional inability to sing because a dust storm was playing havoc with his voice.

Blondie's Debbie Harry joined Arcade Fire on stage during their headline slot last night (Sunday) where she shared vocal duties with Win Butler and Régine Chassagne for a rendition of Blondie's 'Heart of Glass' before lending a hand on the Canadian band's 'Sprawl II (Mountains Beyond Mountains).

Not to be outdone, Drake joined Jhene Aiko for a version of 'From Time' and former Guns N' Roses man Slash played a 'Ace of Spades' with Motorhead.

As if the above wasn't enough, Jay Z and P Diddy joined Nas during his set to celebrate the 20th anniversary of the rappers landmark album Illmatic.

Coachella will return for its second run this weekend, the 18th to 20th of April.