Mixer/producer/engineer F. Reid Shippen is a master at giving classic country iconography a modern framework. There’s the boozy sway of Dierks Bentley’s “Drunk On a Plane,” the mandolin-gets-funky good-time groove of Little Big Town’s “Pontoon,” and the twang/R&B merger of Darius Rucker’s summery “Beers and Sunshine.” Shippen even turned things around with Aerosmith’s Steven Tyler, giving “Janie’s Got a Gun” an acoustic overhaul.