AceShowbiz - Stevie Wonder has paid a visit to his longtime friend Aretha Franklin at her home in Detroit, Michigan as she battles ill health.

Reports suggest the 76-year-old star is "gravely ill" and fighting for her life, but she was well enough to receive visitors on Tuesday, August 14, when fellow soul legend Stevie stopped by to spend some time with Aretha, her publicist Gwendolyn Quinn tells Us Weekly.

The Respect hitmaker revealed last summer (17) that she had been working on an original collaboration with Stevie for her next album, the first to include new material since 2011's Aretha: A Woman Falling Out of Love.

It's not known if the track was completed before Aretha's heath crisis. She had previously covered his song Until You Come Back to Me (That's What I'm Gonna Do), which became a big hit for her in 1973.

Meanwhile, sources tell the publication her ex-husband, Glynn Turman, also checked in on the singer on Tuesday morning, and civil rights activist Reverend Jesse Jackson was due to pay her a visit, too.

The news emerges shortly after the Queen of Soul's nephew, Tom Franklin, confirmed the superstar is "sick", but claimed she and her loved ones are remaining positive about her recovery.

"We believe she'll pull through it, she believes she'll pull through it, and that's the important thing," he added to People.com.

Celebrity friends and fans have been sending their well wishes to Aretha ever since the news of her condition hit headlines on Monday, August 13, and later that night, Beyonce and Jay-Z saluted the music icon as they performed their On The Run II Tour stop in her hometown of Detroit.

"This show is dedicated to Aretha Franklin," Beyonce told the audience. "We love you and thank you for all the beautiful music."

Aretha has been struggling with various health woes in recent years, and secretly underwent surgery to remove a tumour in 2010.

Last year (17), she revealed she was set to retire from touring, and in January, she was forced to cancel a string of shows on doctors' orders. She last performed on 7 November (17) at an Elton John AIDS Foundation event in New York City.