"She's known God as her savior, certainly, but she had to believe that that voice that she has - that very special voice, I call it a gospel voice that comes from the soul, no matter what she's singing, it could be the Star Spangled Banner, but you could hear church right in it", he said.
"Your music has moved and inspired a generation", he added, "so my prayers are with you".
Earlier this year, she was forced to cancel a string of shows on doctors' orders.
Dubbed the Queen of Soul, she announced her partial retirement past year, saying she would release one last album and perform at "some select things".
A person close to Franklin, who spoke on the condition of anonymity because the person was not allowed to publicly talk about the topic, told The Associated Press on Monday that the singer is ill. "Wishing you all the best, queen". According to The Detroit News, more than 100 people gathered at the church to pray for Franklin.More news: Turkey's Erdogan vows USA boycott, but diplomats resume talks
"Family is there with her".
"Like people all around the world, Hillary and I are thinking about Aretha Franklin", Clinton said Monday on Twitter.
"Just read the reports about Aretha Franklin".
Twyman, of Rockville, Maryland, described himself as a longtime fan. "They have not only asked for prayers during this time, but they have also asked for their privacy". After her performance, he said, "Nobody embodies more fully the connection between the African-American spiritual, the blues, R&B, rock and roll the way that hardship and sorrow were transformed into something full of beauty and vitality and hope".
Tuva Johannessen, a tourist visiting from Norway, signed Twyman's get-well card.
He also said the 76-year-old was resting at home and surrounded by family. "She's definitely a queen and she's wonderful so I really feel for her".