Like skinhead punk or bluegrass, zydeco — the jubilant R&B branch of Cajun music — is an intrinsically narrow art form; there’s only so much you can do with it. That hasn’t stopped major labels from scooping up some of zydeco’s leading lights now that it’s in vogue. Buckwheat Zydeco’s wildly eclectic On Track offers more surprises that other albums. Led by accordionist-singer Stanley Dural Jr., Buckwheat has always longed for crossover. Here, the big pop moves are ”You Lied to Me,” a soul romp with sleek female harmonies that could be described as Soul II Creole; the bayou twist given to Solomon Burke’s 1962 R&B hit ”Cry to Me”; and, most astonishing, a rave-up cover of ”Hey Joe,” with Dural playing quasi-Jimi Hendrix licks on the accordion. ”Cooking With Pierre,” written for Pierre Franey’s Cooking in America TV series, shows how this music can be reduced to innocuous dinner-party accompaniment. Overall, though, On Track succeeds in its modest goal — gently dragging zydeco into the 21st century. B