Chicago Opera Theatre was founded 30 years ago as n alternative to the Chicago Lyric Opera. But “with the appointment five years ago of former Glyndebourne chief Brian Dickie as general director, it has begun to offer productions with musical and theatrical qualities worthy of international attention. In its first season in the new, acoustically splendid, Joan W. and Irving B. Harris Theater, Chicago Opera fulfils its new promise with the much-belated Chicago premiere of Benjamin Britten’s 1973 Death in Venice.”