It's fitting that a talent as outsized and legendary as soul giant Isaac Hayes would inspire similarly large tributes from some of his fellow icons.

Hayes, 65, [article id="1592489"]who died Sunday of yet-undetermined causes[/article], is best known to younger audiences for his work as the voice of Chef on "South Park," but over the course of his 40-year career as a singer, songwriter, producer and musician, Hayes left a substantial mark on the funk and soul music of that era.

Moore said it used to bother him that Hayes didn't seem to get the proper respect he deserved for his work as a writer and producer. "Not like the writers and producers at Motown or Quincy Jones — but he was [on that level], in my opinion," Moore said. "He gave me my voice. He taught me, showed me and nurtured my voice. He didn't teach me how to sing, he taught me how to be a better singer. That was Isaac."

Once Hayes went on to become a performer in his own right, Moore said he worried that his old friend didn't understand what it took to command a stage. "He didn't have a choreographer, he didn't have a show," Moore recalled. But he needn't have worried. "Isaac would just get up there and sit down and become one with the song he was doing ... and you would look out and [the women] would be hanging on every word. It made me wish my voice was that deep!"

Bootsy Collins, the former P-Funk and James Brown bassist — whose outfits were often even more outrageous than Hayes' — told MTV News that Hayes' death was like "another pillar out of the building" removed in order to build a new structure he called the "skyway of love."

Collins said he'd spoken with Hayes just last week about a project the pair were working on for BET, and he was finding it hard to believe his friend was gone. "I met Isaac Hayes when I was on the road with James Brown in the '70s," he recalled, "We played a few festivals together. In my later years, I got to know the man behind the music. He was the first official black man to be known as a real rapper, [and he] had nothing but praise for his queens and women of the world."

Another legendary musician who praised Hayes' spirit and song was fellow Rock and Roll Hall of Famer Aretha Franklin, who said in a statement, "[Hayes was] so musically advanced and timeless in his compositions. He was loved and appreciated by so many. He was an enduring symbol of the struggle of the African-American man and was a shining example of soul at its best." R&B diva Patti LaBelle reminisced about the last time she saw Hayes, at a concert they both played in Washington, D.C. "Although he was under the weather, he was still performing," she said. "He was the man — he had 'the show must go on' spirit. In his absence, he will be remembered through his great music. He will forever be in our hearts and souls."

A tribute also came in from the Reverend Al Sharpton, president of the National Action Network and longtime civil-rights leader. "I am deeply saddened by the loss of Isaac Hayes, a true historic world music figure," said Sharpton said in a statement. "Isaac Hayes was the first African-American to win an Oscar for a music score but never lost sight of his commitment to his community and the betterment of mankind. He was more than an artist — he was a trailblazer, he was an innovator." Sharpton was slated to dedicate his evening show on New York's KISS-FM show to Hayes, who was a morning DJ at the station in the late 1990s.

Over the years, MTV News spoke with Hayes on a number of occasions, and each time the man with the legendarily deep and booming voice came off as a music fan first and foremost. Talking about the re-recording of his most famous song for the 2000 "Shaft" remake, Hayes said somewhere "back in my history I did the right thing," speaking of the success he had with the song the first time around.

"I tried to be as real as I possibly could," he said. "And I keyed in on the character, Shaft, the character himself. That was through the suggestion of Gordon Parks, the original director. He said, 'You got to depict the personality of this guy. You got to stick with him.' "

And for a man who Sam Moore said had untouchable skills when it came to wooing the opposite sex, in 1998 Hayes complained that some of today's soul singers were laying it on way too thick in their musical come-ons.

He then offered some advice that could have come straight from Chef, the character he voiced on "South Park."

"When you're talking to a woman, you got to take it very slowly and build," he said. "Anticipation. And by the time you get to the payoff, it's all good."