Tucson's John Convertino and Joey Burns (a.k.a. Calexico) have stumbled upon an apparently endless supply of inspiration. But how to write about the duo without repeating the same cliches about its evocative music? To Calexico's credit, it's virtually impossible. The band so embodies the spirit of the Southwest that to ignore the myriad cross-cultural references in its romanticized Tex-Mex themes—from Mariachi music to spaghetti-western scores—is to miss the essence of Calexico itself. Hot Rail, its third album, won't prick up any ears not already in love with the band, but it demonstrates a newfound sense of nuance that longtime fans may pick up. Having mastered the mysterious mood swings of desert music, Convertino and Burns concentrate as much on the actual songs as the impeccable ambience. Previously unexplored influences such as Serge Gainsbourg and 20th-century avant-garde classical music come to the foreground to complement tips of the hat to composers as disparate as Henry Mancini and Ennio Morricone. "Fade" features a strong cornet solo from Rob Mazurek of Chicago Underground Duo, while "Sonic Wind" alludes to bossa nova by way of cowboy music. Percussive freak-outs such as "Mid-Town" are balanced by beautiful, sun-baked songs like "Ballad Of Cable Hogue" and "Service And Repair," the latter akin to Calexico friend and occasional Giant Sand bandmate Howe Gelb's oblique country. Hot Rail is akin to a series of glimpses from the window of a moving train as it passes through increasingly unfamiliar territory. It should get even better when Calexico finally gets to where it's going.