The teen foursome from Cape Breton makes no missteps on its first international release. If there is any surprise, it may be how quickly Fiona MacGillivray’s singing has grown beyond cute into incandescent. Her take on Ron Hynes’ “Atlantic Blue” sounds like a new regional classic. To keep the trad crowd from getting snippy, there are sufficient jigs and whistles, seasoned with smart choices like a couple of lesser-known Tom Waits numbers. With a lilt here and a cello there, they evoke Cape Breton to the wind-whipped bone. The Cottars stand to embody their home as much as the Rankins have, seeming less likely to tilt into mainstream pop. Maturity, chops and boosters like the Chieftains have the Cottars in position to stick to their strengths, which grow daily.