A year-and-a-half ago, Seiji Ozawa finished up 29 years leading the Boston Symphony, and headed for Vienna to direct the State Opera. “Ozawa seems energized by all the change. Some critics and musicians felt that he had overstayed his welcome in Boston, that 29 years was too long a marriage for any conductor and orchestra. He acknowledges that it was a long time, adding that his style is to work slowly and methodically. But now he finds himself living in an even more musical city, associated with two of Europe’s great musical institutions. And already Vienna has adopted him as its own.”