"Isaac Hayes helped pave the way for so many artists like myself," says Ashanti, who sampled his song, "The Look Of Love," in her hit, "Rain on Me."
"I also had the honor of meeting him several times – he was always so sweet like an older uncle," she says.
"He was a warm, gentle soul," agrees his pal Richard Roundtree, who played the slick title character of the 1971 movie, Shaft, for which Hayes's movie theme song won both an Oscar and a Grammy.
"During those special times when you were with someone that you fancied, if you put on Isaac Hayes, it set a really romantic mood," says Roundtree with a laugh. "You'd put on Isaac Hayes and follow it with Barry White, and it was a special evening."
Lisa Marie Presley also expressed her grief to PEOPLE. "Isaac was one of the more genuine and beautiful souls I have had the privilege to befriend in this life," she says. "He was an incredible friend. My heart goes out to his wife and children."
Singer Dionne Warwick lamented losing "one of my best buddies."
"[I'll miss] the humorous side that he showed few," she says.
Though Hayes was best known in later years as the voice of Chef from South Park, the singer had a solid resume as an actor, including a recurring role on the popular '70s TV detective show, The Rockford Files.
"Isaac added a dimension to the show that we hadn't had before," says Rockford star James Garner. "I will miss him."
The Family Thanks Fans & FriendsHayes's family has been deeply touched by all the kind words.
"We are overwhelmed with the outpouring of support and love from Isaac's fans from every corner of the world," his family said in a statement. "And we thank each and every one of them for their kind thoughts and prayers."
"While he was an iconic figure to many, to us he was husband, father and friend," the statement continued. "We will ever miss his love, wisdom, humor and the familiar comfort of his voice."
Family members said the singer, who had a history of high blood pressure, had recently been treated for various medical conditions. The cause of his death is still being determined.