Flack had been diagnosed with the neurodegenerative disorder, amyotrophic lateral sclerosis (ALS), in 2022.
Following the sad news, Warwick took to X to post a video of her and the musician performing a duet of Killing Me Softly with His Song.
"You will be missed, dear friend," she wrote. "We now say Rest In Peace and receive the loving award the Heavenly Father has for her. I'll miss our conversation about the journey through music we would have, as well as the love of the music we have been able to share."
In his own Instagram Stories post, Lenny Kravitz claimed Flack's music "nourished me throughout my life", while Jennifer Hudson lauded the artist as "one of the great soul singers of all time".
Elsewhere, Queen Latifah listed Flack's accomplishments in a heartfelt message.
"Rest in peace to Howard graduate, classically trained pianist, songwriter, singer, & the first artist to ever win a Grammy for Record of the Year in two consecutive years, Miss Roberta Flack," she commented on X. "Her & her fellow songwriter Donny Hathaway are now reunited."
While Kelly Rowland admitted her "heart just sank" when she learned of the Where Is the Love star's passing.
"Our Dear Ms. Roberta Flack has ascended beyond but what beauty she has left us with!! THANK YOU for your effortless, most beautiful gift!" she praised. "THANK YOU for being apart of the soundtrack to the most tender moments in my life! So Grateful for you!" (Music-News.com)
