Snow died Tuesday in Edison, N.J., said Rick Miramontez, her longtime friend and public relations representative. She had suffered a brain hemorrhage in January 2010.
"Phoebe Snow has made it," Stephen Holden wrote in a 1975 review for Rolling Stone. "On a musical level she shows the potential of becoming a great jazz singer. Among confessional pop songwriters she immediately ranks with the finest."
Rolling Stone described her original compositions on "Phoebe Snow" as "light jazz torch songs" but freer in form and attitude. (Two other songs on the album were her versions of others' material.)
Snow was hard to categorize musically; a Times reviewer early in her career called her style "a helter-skelter amalgam of pop, jazz, blues, gospel and folk." She explained to the New York Times in 2003, "No creative person should ever produce the same thing over and over."
Dennis Hunt, writing in the Los Angeles Times in 1976, said her voice had "a marvelous 'cracked' quality" and she "glides through and glances off notes in an appealing offbeat manner."
But Snow was never able to duplicate her early commercial success. Her career took a backseat to caring for her daughter, Valerie Rose Laub, born in 1975 with severe brain damage.
"It was very, very tight," Snow told the San Francisco Chronicle in 2008. "Occasionally I put an album out, but I didn't like to tour and they didn't get a lot of label support. But you know what? It didn't really matter because I got to stay home more with Valerie and that time was precious."
She sang commercial jingles for such companies as Stouffer's and General Foods, which she said paid well.
Her daughter died in 2007. A few months later, Snow started performing again, trying to deal with her loss.
"Right now it's beyond a hole. It's a black hole," she told the Record of Bergen County, N.J., in 2008. "I don't even know how to describe that vacancy because it was such an intense relationship. We lived together for 31 years. She was a perennial child. I was her primary caregiver.... We were best friends. It was beyond a loss. I don't even know what word to use."
Snow was born Phoebe Laub on July 17, 1950, in New York City and grew up in Teaneck, N.J. As a youngster she studied piano, then switched to the guitar.
"I always wanted to be the greatest woman guitarist alive," she told The Times in 1976. "I had fantasies about being a female Jimi Hendrix. I would go to his concerts and watch all the things he did. But I guess I just wasn't meant to be a superstar guitarist."
Taking guitar lessons affected her singing style.
"I finally said, 'I can't play these guitar lines but maybe I can sing them.' I tried to sing the way a guitar sounds and the way a saxophone sounds too."
Her poetry became the basis of her lyrics, and she started playing at New York clubs. She signed with Shelter Records in 1974.
She moved to Columbia Records in 1976 after sometimes nasty legal wrangling with Shelter. "Second Childhood" earned her a second gold record, but subsequent Columbia releases did not sell as well. She left the label at the end of the 1970s.
After being quiet most of the 1980s, Snow recorded a comeback album in 1989's "Something Real" for Elektra.
She released a live album in 2008.
"I faded away for a while out of necessity," she told The Times in 1998. "In hindsight, I missed out on some good or productive years. On the other hand … I really made the only choice I could under the circumstances."
Snow's marriage to Phil Kearns ended in divorce. She is survived by a sister, Julie Laub.