King had recorded a couple of minor hits in the early '60s, and the core of the Tapestry band had made two earlier albums, one of them under the name The City. But Tapestry was where her ­singular gifts ­blossomed. As Taylor tells Billboard, his ­longtime friend "decided to own her voice -- no gauze on the lens, no affected ­technique -- writing from her own personal ­experience and her own heart. She was ­herself, it read as being absolutely ­sincere, and it ­connected." King rarely had ­written words for her music before, but she came up with ­gorgeously plain-spoken ­lyrics about the difficulties and joys of grown-up love. "So Far Away," she notes, was inspired by missing her family -- the two daughters she had with Goffin, Louise and Sherry; and her second husband, bassist Charlie Larkey -- while on the road ­playing piano for Taylor in 1970.

Tapestry's first single, "It's Too Late"/"I Feel the Earth Move," spent five weeks atop the Hot 100 and featured words by another Laurel Canyon friend, lyricist Toni Stern. ("She always gave me a completed lyric that was so evocative on the page that the music ­practically wrote itself," says King.) And King's own reinterpretations of a pair of hits she and Goffin had written for other acts -- The Shirelles' "Will You Love Me Tomorrow" and Aretha Franklin's "(You Make Me Feel Like) A Natural Woman" -- transformed them into reports from the California front of the sexual revolution.

Tapestry was the kind of album in which listeners could hear their own lives reflected. "It might have been the Vietnam War, the violence, the cultural divide," says King. "People around the world have told me Tapestry helped them reconnect with basic human ­feelings when they really needed that." The LP spent 15 ­consecutive weeks at No. 1 on the Billboard 200 (the longest ever by a female solo artist at the time), 46 weeks in the top 10 and the better part of the '70s on the chart, yielding four Grammys and 10 ­million copies sold in the United States, according to the RIAA. It also became the cornerstone of King's career as a performer -- and, more recently, of her jukebox musical Beautiful. (She'll be feted at the Kennedy Center Honors in December.) "I had no idea how big Tapestry would be," says King. "One word sums up how I feel about that: gratitude."

Additional reporting by Frank DiGiacomo.

​This story originally appeared in the November 21 issue of Billboard.