Sick soul star D'angelo has pulled out of a planned performance at California's Outside Lands festival on Friday (09Aug13) as he continues to recover from a mystery "medical emergency".

The Brown Sugar singer has scrapped a series of U.S. concerts after he was recently hospitalised with a "serious" illness, and now he has cancelled his last remaining summer gig at Outside Lands as a result of his health troubles.

Funk legend Nile Rodgers and his Chic bandmates have been recruited as last-minute replacements and event organiser Allen Scott, of Another Planet Entertainment, is confident fans will still enjoy the festivities.

He says, "We hope that D'Angelo has a speedy recovery, and we are grateful to Nile Rodgers and Chic for stepping in at this late hour. Chic is still one of the greatest live bands around and I can guarantee that they are going to bring the party to Outside Lands on Friday."

Details about D'Angelo's illness have not been made public, but a spokesperson for Chicago, Illinois' House of Blues, where the singer was due to perform on Wednesday (07Aug13), reveals he "should be Ok".