In 1955, while in the midst of working on a musical version of Voltaire's Candide with the distinguished American playwright Lillian Hellman, Leonard Bernstein composed French and Latin choruses as incidental music to the play The Lark adapted by Miss Hellman from the original French version by Jean Anouilh. Since the drama was about the trial of Joan of Arc, Bernstein’s music was deliberately evocative of the medieval era. In fact, the music was performed (on tape) by seven members of the...