Is it folk? Country? Ambient? No matter how you classify the music of Los Angeles’ Eastmountainsouth, one thing is certain: It is gorgeous. The group’s debut displays a formal and melodic beauty uncommon on opening bows. The double-threat writing/singing front line of Kat Maslich and Peter Adams handsomely updates Southern roots concepts, ably aided by the firm guiding hand of veteran musician/producer Mitchell Froom. Subdued and intoxicating revisions of traditional material like “Hard Times” and “The Ballad of Young Alban and Amandy” nestle comfortably against affecting originals (“Ghost,” “You Dance,” “Show Me the River”). The band has hypnotized audiences at its L.A. shows. A following at noncommercial and adventurous Americana outlets will hopefully ensue.—CM