Grammy-winning musician Roberta Flack has ALS, commonly known as Lou Gehrig’s disease, and can no longer sing, a representative said.

The progressive disease “has made it impossible to sing and not easy to speak”, Flack’s manager Suzanne Koga said in a release.

“But it will take a lot more than ALS to silence this icon.”

The announcement of the amyotrophic lateral sclerosis diagnosis comes just ahead of the premiere of Roberta, a feature-length documentary debuting on Thursday at the DOCNYC film festival.

The release says that the Grammy-winning singer and pianist, now 85, “plans to stay active in her musical and creative pursuits”.

Flack is known for hits such as Killing Me Softly With His Song and The First Time I Ever Saw Your Face, the latter of which catapulted her into stardom after Clint Eastwood used it as the soundtrack for a love scene in his 1971 movie Play Misty For Me.