Song for Sharon

“Song for Sharon” is a nearly nine-minute letter from Joni Mitchell in New York to her friend Sharon back home in Saskatchewan, in which Mitchell tries to explain — or maybe admit — what has happened to her life since she left. Jaco Pastorius plays the bass as the second voice of the song, a countermelody that keeps moving like the river Mitchell keeps describing.

It is one of the great letter-songs in American music: specific, unhurried, full of the kind of detail that only surfaces when you have eight and a half minutes to get where you’re going. The grief in it is for the version of herself who might have stayed — a self that is still technically alive and still technically available if she ever wanted to go back, and which she knows, by the end of the song, she never will.