Mahsa Vahdat and Mighty Sam McClain

Everyone always says the blues are universal; now, World Music Institute puts that theory to the test with a concert by the duo of Persian singer Mahsa Vahdat and Louisiana bluesman Mighty Sam McClain. However unlikely the pairing (and however slick the production on their CD, A Deeper Tone of Longing), the soulfulness of these disparate artists is palpable and complementary.