She inspired songs--Leon Russell wrote "A Song for You" and "Delta Lady" for her; Stephen Stills wrote "Cherokee." She co-wrote songs--"Superstar" and, uncredited, the piano coda to "Layla." She sang backup for Eric Clapton, Joe Cocker, and Stills before finding fame as a solo artist with such hits as "We're All Alone" and "(Your Love Has Lifted Me) Higher and Higher." Following her from Lafayette, Tennessee, to her becoming one of the most sought-after...