The senior PR executive worked with Elton John, New Edition, Bobby Brown and other artists during her trail-blazing career.
“Thank you, Joey…for keeping the band’s music alive for so long and for being a friend to us all,” a Facebook post read.
Stone had two No. 1s on the Adult R&B Airplay chart and one on the Top R&B/Hip-Hop Albums chart, and was nominated for three Grammys.
The singer had revealed his cancer diagnosis in February.
"I know great grief is born only of great love," Kylie Jenner wrote in a heartfelt tribute to the late artist.
The singer-songwriter notched his first Hot 100 hit at just 12 years old.
The Juilliard-trained hitmaker was diagnosed with cancer in December, his family said.
No cause of death was available for the singer whose "The First Time Ever I Saw Your Face" was featured in Clint Eastwood's 1971 directorial debut.
"Bill was a gentle man and a gentleman, wise beyond our times," his label wrote.
The soul icon who formed the group with the late Curtis Mayfield, notched 38 career Billboard Hot 100 singles over his long career.
