HIGH NOTE: Opera attendance grew by 21%...

HIGH NOTE: Opera attendance grew by 21% nationally over the previous year, according to a new survey (F2), but jumped by an even greater amount--31%--at the Orange County Performing Arts Center. . . . The local increase can be attributed to a visit last January by the New York City Opera, which drew almost 19,000 people in seven performances. . . . Attendance sagged, however, at Costa Mesa-based Opera Pacific.