Groove has always been an essential element for the jazz guitarist John Scofield, expressing itself in ways either subtle or obvious, depending on the setting. “Piety Street” (Emarcy), released last week, falls in the obvious category, with a fortunate twist: it’s Mr. Scofield’s old-time gospel album, recorded in New Orleans with a band drawn mainly from that city’s robust R&B scene. It’s a basic concept, and it makes all kinds of sense.