Dr Dre made a surprise appearance with his "California love", and a frail Joni Mitchell sang from a chair. Additionally, Stephen Stills and Graham Nash from Crosby, Stills & Nash performed together for the first time in a decade.
As soon as Los Angeles gets into trouble, the musicians are there. And I'm proud to be one of them, said Stephen Stills from the stage.
On two stages in two arenas, the artists performed to help raise money for those affected and to finance the rebuilding after the massive fires in the Los Angeles area recently.
Furthermore, the remaining members of Nirvana reunited for a surprise performance, with singers St Vincent, Kim Gordon, and Joan Jett. They also had Dave Grohl's 18-year-old daughter Violet Grohl on stage.
Other artists who appeared were Earth Wind & Fire, Katy Perry, and Green Day. Actor Billy Crystal, who has lived in the area for 46 years, told the audience about how he lost his home to the fire.
The fires started raging on January 7 and the two largest destroyed everything in their path in Pacific Palisades and Altadena. At least 29 people died and the costs for rebuilding are expected to be astronomical.