BLAKE SHELTON Red River Blue [Warner Bros.] Blake Shelton, known outside the mainstream country world as resident cornball on NBC’s The Voice, swarmed to the top of the charts recently with the hillbilly valentine “Honey Bee.” On Red River Blue, perhaps the most pop-sounding collection in his catalog, he works best when exposing the different shades of domestic partnerships. The harmonies of Nashville’s leading women (“I’m Sorry” with...