Grammy-winning jazz singer Al Jarreau, who transcended genres over a 50-year career, has died at the age of 76.

The singer died at a Los Angeles hospital on Sunday, just days after announcing his retirement from touring because of exhaustion, his manager Joe Gordon confirmed.

His website said he died surrounded by his wife, son and a few other family members and friends.

Al was admitted to hospital earlier in the week and was said to have been improving slowly. The cause of his death was not revealed, but he had experienced a number of respiratory and cardiac issues in recent years.

The Milwaukee native won seven Grammys over the course of his half-century in music. His biggest single was 1981′s We’re In This Love Together from the album Breakin’ Away.

Al was also a vocalist on the all-star 1985 track, We Are The World, and sang the theme to TV’s Moonlighting.

“We feel very fortunate to have worked with Al, one of the most distinctive and extraordinary vocalists in the music,” said Concord Records president John Burk in a statement. “He was truly a force of nature and a beautiful human being that will be fondly remembered and deeply missed by us all.”

Al Jarreau (Efrem Lukatsky/AP)Al Jarreau (Efrem Lukatsky/AP)

Al is one of the few artists to have won Grammys in three separate categories — jazz, pop and R&B. Time Magazine once called him the “greatest jazz singer alive”.

His final album, My Old Friend: Celebrating George Duke, was released in 2014.

Al is survived by his wife, Susan, and a son, Ryan.