Vandross has won four Grammys

The album Dance With My Father tops the chart, ahead of Radiohead's new album and Metallica's St Anger, selling more than 400,000 copies.

Jeff Davidson, of US chain HMV, said: "The genuine outpouring of emotion for Luther Vandross has been amazing. He's outpaced any possible projection that we had imagined. "

The singer's condition has improved greatly since suffering a stroke in April

"I am happy to report that Luther Vandross continues to improve and he is more and more responsive each day," said Carmen Romano, the singer's business manager.

He added: "Perhaps most significantly, he is no longer in the intensive care unit. I feel as though I am watching a modern day miracle."

Vandross' mother blamed her son's hectic schedule for him suffering a stroke.

Mary Vandross, said: "He just worked himself to where he is right now."