Imagine our southern border without concrete walls, coyotes, and Minutemen vigilante patrols. Imagine John McCain still believed in realistic immigration policy. Imagine music free to traverse this open landscape (it's easy if you tryâ¦), drawing mariachi blasts from the south and pedal steel cries from the north, and you get a sense of Calexico's sound. This border hopping gives the Tucson band an impressive range. The core duo of singer-stringer Joey Burns and percussionist John Convertino works with an oft-shifting cast that adds harmonica, trumpet, cello and glockenspiel. They proved their alt-folkie acoustic chops collaborating with Iron and Wine a few years ago and returned to their signature Americana-meet-Tejano rock sound on this month's "Carried to Dust," conceived as a Southwestern travelogue. Unlike your average "Mexican" fry pit serving up burritos and chimichangas and calling them authentic, Calexico embraces its border country home. And, yes, horns in rock 'n roll can be a dangerous gambit. These guys do it right.