A medical emergency has scratched neo-soul singer D'Angelo from Friday's lineup at the Outside Lands festival in San Francisco's Golden Gate Park.

The ailment, which was not disclosed, marks the latest setback in D'Angelo's prolonged attempts at a career revival.

Outside Lands organizers released a statement saying the singer "expresses his sincere regret due to this unfortunate circumstance."

His replacement was an intiguing choice: The famed disco band Chic featuring the guitarist, producer and songwriter Nile Rodgers. Chic is best know for such 1970s dance-floor staples as "Le Freak" "I Want Your Love"and "Everybody Dance." Rodgers, however, has maitained a steady career since then, collaborating with everyone from Diana Ross to David Bowie to Duran Duran. His riffs were most recently featured on several tracks in Daft Punk's new album, including the smash hit "Get Lucky."

D’Angelo, shown performing at the  "Made In America" music festival in September 2012, has canceled his appearance at the Outside Lands
D'Angelo, shown performing at the "Made In America" music festival in September 2012, has canceled his appearance at the Outside Lands festival in San Francisco on Friday. Photo by Charles Sykes/Invision/AP archives) ( Charles Sykes )

As for D'Angelo, the Los Angeles Times reported he has canceled a string of performances over the last week or more, including last weekend's Spirit Festival in Maryland, as well as shows in Chicago, Minneapolis, San Diego and New York.

The Times said an agent for the singer described D'Angelo's ailment as "serious, but he should be OK."

D'Angelo is still working on a follow-up album to 2000's "Voodoo."



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