On this day in 1943, Roberta Joan Anderson was born in Fort MacLeod, Alberta, Canada. As Joni Mitchell, she revolutionized the singer/songwriter genre with her seminal late-'60s and early-'70s albums, in which she eloquently poured out her heart and soul.

After battling polio as a child, the young Roberta Anderson studied art in Saskatoon, Saskatchewan, Canada, and developed an interest in folk music. She moved to Toronto, where she began playing guitar and singing in folk clubs. In 1965, she married folk singer Chuck Mitchell.

The couple moved together to Detroit, Mich., where they had an act, but soon separated. On her own, Joni Mitchell became a critical favorite, and she eventually relocated to New York City. Artists such as Tom Rush and Judy Collins (who had a smash with Mitchell's "Both Sides Now") began recording songs written by Mitchell, who was signed by Reprise Records in 1967.

Mitchell's eponymous debut, produced by David Crosby, was released in 1968. The following year's Clouds contained her own version of "Both Sides Now" and "Chelsea Morning." Ladies of the Canyon (1970) featured several of Mitchell's best-known tunes, including "Woodstock" (which she wrote from others' recollections, since she didn't attend the epochal music festival), "The Circle Game" and "Big Yellow Taxi."

Critics hailed 1971's Blue as a masterpiece. On the LP, Mitchell sang painfully confessional songs about the daughter she put up for adoption ("Little Green") and troubled love ("A Case of You").

In 1974, Mitchell reached her commercial apex with the jazz-tinged Court and Spark (a #2 hit in the U.S.), featuring her highest-ever charting single, "Help Me." The real experimentation began with The Hissing of Summer Lawns (1975), which brought African drums and complex horn arrangements into her work.

Hejira (1976) confused many critics and fans when it was released, but its meandering songs about travel are now generally considered some of Mitchell's best music. Mingus, Mitchell's 1979 collaboration with jazz great Charles Mingus, got her dropped from pop radio, and her commercial status never really recovered.

In the '80s, Mitchell experimented with soul (on Wild Things Run Fast) and synthesizers (on the politically-charged Dog Eat Dog) and took a long hiatus from touring.

The '90s saw Mitchell re-emerge in her singer/songwriter mode. She returned to more confessional folk-oriented writing on albums such as the Grammy-winning Turbulent Indigo (1994), and was inducted into the Rock and Roll Hall of Fame in 1997.

After being reunited with her daughter via the Internet, Mitchell released the happier Taming the Tiger this year. The disc finds the usually serious composer singing playfully about the joys of sex on tracks like The Crazy Cries of Love (Real Audio Excerpt). Mitchell also began touring again, often on co-bills with Bob Dylan.

Singer/songwriter Alana Davis said this year about Mitchell: "I was 17 when I found [the music of] Joni. She changed my life. She spoke to me, as a female songwriter, in a way that no one ever has. She showed me how honest we can actually be."

Other artists who have sung Mitchell's praises recently include: Natalie Merchant, Janet Jackson, Sarah McLachlan, Stevie Nicks, John Mellencamp, Robert Plant, and Bjork.

Other birthdays:

Mary Travers (Peter, Paul & Mary), 61; Johnny Rivers, 56; Jellybean Benitez, 41; Liam O'Maonlai (Hothouse Flowers), 34; Dino Valenti (Quicksilver Messenger Service) 1943-1994.