In her nearly four decades as a musician and lyricist, Joni Mitchell (born 1943) has spanned the fields of folk, pop, rock, and jazz with 23 albums. Her willingness to change direction without warning has frequently left fans upset, but her free spirit has endowed her creativity. By 2002, Mitchell had achieved the stature of Bob Dylan and influenced the likes of Madonna and Prince. Even Frank Sinatra recorded one of her songs.

Joni Mitchell was born Roberta Joan Anderson on November 7, 1943, in Fort Macleod, Alberta, Canada. She was daughter of Bill Anderson, a grocer, and his wife Myrtle, a schoolteacher. Mitchell moved with her parents to North Battleford, Saskatchewan, after World War II ended. At the age of nine, she and her family would move again to Saskatoon, Saskatchewan, which Mitchell today considers her hometown.

After a friend introduced her to classical music, Mitchell asked her parents whether she could...