Although the Ballet Theatre came to Boston right after the Ballet Rousse, a large and appreciative audience poured into the Opera House last Monday to see its opening. This is not surprising, because the corps presented an interesting and highly polished performance.

In Les Sylphides, Mary Ellen Moylan was particularly graceful--she had the quickness of a butterfly. As one man in the midst of many women, Michael Lland appeared relaxed to the point of boredom, but he executed a few grandes jetes with case. Soft, pale green lighting enhanced the ensemble's movements, which, except for occasional bad timing, were precise.

Le Jeune Homme et La Mort a Boston, premiere, is a Jean Cocteau creation based on the Orpheus and Eurydice myth. Earthy and passionate, Jean Babilee and Nathalic Philippart conveyed well the brutality, horror, and the final beauty of this modern ballet. The acrobatic elements in the choreography, however, tended to detract from the symbolic force of the legend.

Fortunately, the frequent intermissions set apart Swan Lake's classical pas de deux from the modern dances, so that the transition from new to old was not too jarring. This pas de deux is strictly an exhibition piece and the celebrated Igor Youskevitch performed it with amazing skill, as did his partner, Alicia Alonso. It is too bad that this duo appeared for such a short time.

John Kriza, as the sly, ribald Bluebeard in the ballet of the same name, was not only deft at comic gestures, but a lively dancer. The entire corps, as a matter of fact, was in excellent form throughout the whole performance.