Johanna Schwartz’s informative documentary follows several Malian musicians, who have been forced to flee Timbuktu and regions in the north after instability leads to an Islamist takeover. There, under newly imposed Sharia law, all forms of entertainment are banned. The performers — which include a group of young men with a more modern sound and older women who perform traditional music — bemoan the state of things (“If you take away music, Mali is dead”), while refusing to give up. Some performers travel to the U.K. to raise awareness; others lead songs in refugee camps. An eventual return to Timbuktu is bittersweet: The city has been hard hit, but a hastily arranged street concert underscores how deeply music is felt in this culture.