The BBC's "Legend" series has focused on Joni Mitchell, tracing her Canadian roots out west, and outlining her early experiences and influences, including her battle with polio as a child, how she almost became a painter, and how her career evolved.

If this interests you, the BBC has put it online for free with no geographic restrictions and no commercials. But if you want to hear the show, do it soon - as the British broadcaster often does, this one is time limited and will only remain online for the next 29 days.

"In Legend, we follow Joni from her ‘flatlander’ childhood on the Canadian prairies, through the folk clubs of Toronto and Detroit, to a redwood cottage in L.A.’s Laurel Canyon, to a cave in Crete, to a deserted desert highway, to recording studios and stages around the world. From her earliest home recordings to masterpieces like Blue, Court and Spark, and Hejira, we explore some of the stories behind her best-loved songs."

Hear it here.