Ms. James was reported to have been diagnosed with dementia and leukemia. Her illnesses were made public as part of a court battle between her husband and her children concerning $1 million of the singer’s fortune, in part to cover her health expenses.
Ms. James attracted a broad following in the 1960s with her interpretations of jazz-inflected pop. Many of her songs, especially her 1961 string-backed version of the big-band-era pop standard “At Last,” are frequently heard on film and television soundtracks.
She influenced later singers from Janis Joplin to Bonnie Raitt. Raitt called her “the bridge between R&B, blues and pop singing. . . . Like Ray Charles, Etta brought the passion of gospel, R&B and gutbucket raw soul music into the mainstream in a way that very few people have ever crossed over.”
Ms. James made more than 40 albums and received the 1994 Grammy for best jazz vocal performance for “Mystery Lady: Songs of Billie Holiday.” She also experimented with rock music and was the opening act for the Rolling Stones in the late 1970s and early 1980s.
She saw herself foremost as a blues musician. In her 1995 autobiography, “Rage to Survive,” Ms. James wrote, “No matter how pop or schmaltzy a song, I can’t help but put a gospel and blues hurting on it.”
She often made a connection between her music and her anguished life, which included heroin addiction, drastic weight fluctuations and a troubled childhood.
She had been born to a 14-year-old single mother with a rebellious streak. Ms. James once wrote that if her mother was going to be bad, “I was going to be superbad.” And so she smoked marijuana, snorted cocaine and shot heroin. She associated with gangsters and pimps. She was arrested for forging prescriptions and writing bad checks. When not in jail, she said, she was involved with abusive men, some of whom nearly beat her to death.
She said the Betty Ford Center weaned her off drugs in the late 1980s; her cocaine habit began while on tour with the Stones, she said.
Even during the worst of times, Ms. James recorded well-received albums, and reviewers noted how her personal turmoil seemed to enhance her singing.
She said the song “Feeling Uneasy” on the 1974 album “Come a Little Closer” illustrated her experience undergoing drug treatment. Critic Richie Unterberger called the performance one of her career highlights, emphasizing the “wrenching, near-wordless scat-moan vocal over a suitably languorous, melancholy blues-jazz arrangement.”
Ms. James told the trade publication Billboard in 2001: “I don’t pick a song ’cause I think the music sounds cool. . . . I don’t want to sing ‘Fly me to the moon and let me swing amongst the stars.’ I want to sing something that either I’ve experienced or that I know is real.”