There’s something reassuring about international ska bands, a comfort that comes from knowing that although a band may hail from half a globe away, their music can still sound like it was recorded next door. The French outfit Babylon Circus, which plays an 8 p.m. show at Alverno College tonight, puts a few globe-trotting twists on the textbook ska sound—there’s a lot more Bob Marley in the vocals than usual, and an occasional Balkan Gypsy shuffle to the guitars—but their underlying ska rhythm is as familiar as it is universal.