Red Hot Chili Peppers and DJ Avicii helped to get Lollapalooza 2012 rocking again on Saturday night (04Aug12) after a powerful storm shut down the Chicago, Illinois festival for three hours.

Organisers were forced to evacuate 60,000 fans from Grant Park on day two of the 21-year-old event after receiving dangerous weather warnings.

Ocean told the audience, This is really important to me after what I said last month

Heavy rain drenched the grounds but the gates re-opened later that night when the thunderstorm had passed, and rockers Franz Ferdinand and soul star The Weeknd helped to get the party started again as festival-goers came back out to enjoy the remainder of the evening.

Dance DJ Calvin Harris and Bloc Party also performed after the rain clouds cleared, but it was the Red Hot Chili Peppers who proved to be the big draw as one of the night's headliners.

As some fans began to dance barefoot in a big puddle of water in front of the main stage, bassist Flea warned the audience to "be kind, be gentle and be nice".

Meanwhile, Avicii treated the crowd at his set to a spectacular light show as R&B sensation Frank Ocean delighted music lovers with his falsetto as he performed tracks from his critically-acclaimed new album Channel Orange in a more intimate stage setting.

And the singer used the opportunity to thank fans for their support after recently revealing his first love was a man.

Ocean told the audience, "This is really important to me after what I said last month. It's taken the fear away, so thank you".

Black Sabbath and The Black Keys headlined the opening night on Friday (03Aug12), while Jack White, Justice and Kaskade will close the festival on Sunday (05Aug12).