DR. JOHN Locked Down [Nonesuch Records] Few could blame Dr. John (aka Mac Rebennack) if he opted to coast on his towering reputation in New Orleans music. But this new album proves he has no such intentions. Spearheaded by the Black Keys’ Dan Auerbach—who produced and co-wrote the material—Locked Down sounds like a 21st century version of the R&B gumbo Dr. John served up at the turn of the ’70s. The opening title track sets the tone....