Donny Hathaway emerged at the dawn of the ‘70s with songs about black consciousness like “Be Real Black for Me” (a duet with Roberta Flack) and “Voice Inside (Everything Is Everything).” But he had a playful side as well. “Valdez In the Country” showed that he had a jazz player's knack for improvisation, and “Magnificent Sanctuary Band” is a rave-up as rousing as an afternoon barbecue.