R&B singer-songwriter Luther Vandross is recovering in a New York hospital after suffering a stroke.
Vandross: From backing singer to solo artist
The Grammy-winner suffered the stroke just days before he was due to celebrate his 52nd birthday, which is on Sunday.
Vandross fell ill at his home in Manhattan on Wednesday.
Spokeswoman Lois Najarian declined to comment on the extent of his stroke, or whether his motor skills had been impaired.
But the Associated Press news agency reported a source had said the stroke was serious, although the singer was conscious.
Ms Najarian said Vandross had been in good health before the stroke.
Vandross, who has sold more than 20 million records worldwide since pursuing his solo career, won four Grammy awards in the 1990s.
His hits include Jump to It, Here and Now, and Don't Wanna Be a Fool.
Apart from his own singing and song writing, he also produced for stars such as Aretha Franklin, Dionne Warwick, Diana Ross and Whitney Houston.
Throughout his life, Vandross has battled weight problems and admitted once hitting the scales at well over 300 pounds.
He has also suffered from hypertension and diabetes.
"If I'm emotionally distraught, then eating is my coping mechanism", he told Britain's Q magazine in 1991.
He said in 2001 that he was planning to write a book about his most successful attempts to shed weight.
Vandross is due to release his 15th album in the US in June.