The winning genre wasn’t just all-American, it was a return to the kind of conventional country and western music that keeps Nashville afloat and made Carrie Underwood the show’s biggest-selling star.  Mr. McCreery, with his sweet Alfred E. Neuman face and uncannily deep voice, was a throwback to an earlier generation of country stars like Mel Tillis. Moments after winning, he told Ryan Seacrest, “I got to thank the Lord first, he got me here.”