Stevie Wonder performance caps emotional Prince tribute at LA City Hall. A downtown Los Angeles park on Friday drew a jubilant crowd of purple-clad Prince fans, who traveled from across Southern California for a musical celebration of the late singer’s life.

In perhaps the most stunning moment of the evening, music legend Stevie Wonder surprised the more than 5,000 fans by swooping in and singing Prince’s hit “Purple Rain.”

Prince was Wonder’s friend and Wonder owns radio station KJLH 102.3, which helped sponsor Friday’s event.

Among the other musicians taking part in the tribute were Grammy winning-singer Faith Evans, R&B musicians Eric Benet and Aloe Blacc and gospel singer-songwriter Deitrick Haddon — each of them performing some of Prince’s best-known songs.

The crowd filled Grand Park, site of a hastily organized memorial for Prince, who died last month at age 57.

Los Angeles Mayor Eric Garcetti and others politicians, including L.A. City Councilman Marqueece Harris-Dawson, helped organize Friday’s event.

Harris-Dawson told the crowd that L.A. played a big role in Prince’s career as he sang in Hollywood clubs before making it big.

“His career took off on Sunset Boulevard,” Harris-Dawson said.

The three-hour concert marked a major test for both City Hall officials and organizers, who put together the free event in just over a week.

Harris-Dawson said in an interview Friday that he was approached last week by South L.A. activist Najee Ali about putting on the event. City Hall was picked because “it’s a symbol in the entire Southern California region,” Harris-Dawson said.

Prince Rogers Nelson, known as Prince, died on April 21 at his Paisley Park estate in Chanhassen, Minn.

His death prompted an emotional reaction from L.A. officials, who illuminated City Hall in purple lights and released statements praising the singer.

Friday’s event gave the normally-staid governmental corridors of City Hall a festive backstage feel. Performers and concert guests milled about the hallways, snacking on pizza and burgers just steps away from City Council chambers.

The cost of the event is still unknown, as the Los Angeles Police Department continues to tally the price of patrolling the gathering, officials said.