La sonnambula used themes from a Vincenzo Bellini opera that had a libretto by whom?
La sonnambula (Balanchine): La sonnambula "(The Sleepwalker)" is a ballet by the co-founder and ballet master of New York City Ballet, George Balanchine, made to Vittorio Rieti's music using themes from the operas of Vincenzo Bellini including "La Sonnambula", "Norma", "I Puritani" and "I Capuleti e i Montecchi" (1830–35) and with costumes by Karinska.
i don't know