This wasn't really a play, but more like a musical revue. Here's the review Deb found:
"When All the Slaves Are Free: The Words and Music of Joni Mitchell finished a critically acclaimed and well-attended run at Ottawa's Great Canadian Theatre Company earlier this month. The revue was created and directed by Bryden Macdonald, who also wrote and directed similar productions based on the work of Leonard Cohen and Carole Pope. Backed by jazz piano, percussion and bass, singers Elizabeth Beeler, Susan Henley and Mary Kelly took audiences on a theatrical journey through Joni's three-plus decades of work, performing 13 of her songs including The Circle Game, Big Yellow Taxi, Both Sides Now , Passion Play (When All the Slaves Are Free), Cherokee Louise and Hejira. The show ran from September 12 until October 5, and was sold out nearly every night."
Great Canadian Theatre Company holdover announcement
(Contributed by Deb Messling)