LOS ANGELES (AP) _ Funk legend Rick James peaked in 1981 with ``Super Freak,'' a song so enduring that a strain of its infectious bass line powered the MC Hammer hit ``U Can't Touch This'' nearly a decade later.
But James' career never had the staying power of his signature hit, and the singer's life and music languished through cocaine addiction and a prison term. In his final days, James made a comeback bid that included playing along with routines by comedian Dave Chappelle that parodied his history of erratic behavior.
James, who was 56, died in his sleep Friday at his residence near Universal City, said publicist Sujata Murthy. He lived alone and was found by his personal assistant, who notified police, she said.
An official cause of death was not given. Police said James died of natural causes. His three children _ daughter Ty and sons Rick Jr. and Tazman _ said through a spokeswoman that they believe their father died of heart failure.
``The spirit lives on,'' said the singer's son, Rick James Jr. ``I want to thank everybody once again. ...All our prayers go out to the living as well as those who pass on.''
James was a diabetic and had a pacemaker, Murthy said. An autopsy and toxicology exam were scheduled for Saturday, said coroner's spokesman David Campbell.
Friends and colleagues described James as a funk visionary for his grinding, otherworldly songs that were almost gleefully sexually explicit.
``He created another kind of rhythmic style for R&B music,'' said Smokey Robinson, who recorded ``Ebony Eyes'' with James. ``Rick was very unique in his presentation and he was very instrumental in the careers of a lot of other Motown artists.''
Hammer's ``U Can't Touch This'' earned the Grammy for best R&B song in 1990 for both Hammer and James.
And R&B songstress Teena Marie recorded the sultry classic, ``Fire and Desire'' with James. The two toured together this summer.
James, who also played bass, was honored in June by the American Society of Composers, Authors and Publishers with the Rhythm & Soul Heritage Award. Motown founder Berry Gordy Jr. presented the award.
``His creative abilities, his instincts about music and production were just awesome,'' Gordy said Friday in a statement, calling James ``a pioneer who took Motown in a whole new direction.''
James went to work for Motown in the 1970s and got the chance to record an album, ``Come and Get It,'' which was released in 1978 and produced the hit ``You and I.''
The early '80s were good to James. In 1980, he found hits in the singles ``Fool on the Street,'' ``Love Gun,'' ``Come into My Life'' and ``Big Time.'' The following year came ``Give it to Me Baby'' and ``Super Freak.''
After a decade at Motown, James left the label as the sexually graphic themes of his music conflicted with its conservative approach to pop music.
``They never totally understood what I was trying to do, where I was trying to come from with my music,'' he said in a 1988 interview with The Associated Press. ``For the whole 10 years, it was a constant battle in me trying to acquaint them with what I wanted to say and how I wanted to say it.''
At the time he said he had freed himself from a cocaine addiction that was costing him $10,000 to $15,000 a week.
``My lawyers and my accountants and friends really saw it before I did. They saw that my usage of coke was getting to be a million-dollar-a-year habit. I didn't see it until I went into rehab and I didn't understand it until I got out.''
Born James A. Johnson Jr. in Buffalo, N.Y., on Feb. 1, 1948, James said he got caught up in living the ``bad boy'' persona he had cultivated.
``There was a time where I was just trying to live the image wholeheartedly; I wasn't thinking about the person, James Johnson,'' he said. ``I mean, Rick James was just a man-made image, the image I created. Just trying to live Rick James almost killed me.''
James was convicted in 1993 of assaulting two women. The first attack occurred in 1991 when he restrained and burned a young woman with a hot pipe during a cocaine binge at his house in West Hollywood. He was free on bail when the second assault occurred in 1992 in James' hotel room. He served more than two years in Folsom Prison.
In 1997, he released a new album, but a year later he suffered a stroke while performing at Denver's Mammoth Events Center, derailing a comeback tour. In 1998 he underwent hip replacement surgery.
James had enjoyed a bit of a revival recently, in part because of comedian Dave Chappelle portraying him as violent and arrogant on his ``Chappelle's Show.'' James himself appeared on the Comedy Central skits.
James also had his own girl group, The Mary Jane Girls. The foursome had a huge smash in the James-penned hit, ``All Night Long.''