One night, 41 years ago, the Budapest Opera, had a crisis of another sort. It was nearly curtain time, and the conductor was ill. Who would conduct Carmen? In desperation, the director grabbed the 18-year-old singing coach, and ordered him into the pit. "I had no preparation," says Fritz Reiner of that night. "It was sink or swim. I swam."
In time, Fritz Reiner's swimming got better and bolder. He was given a regular conductor's job in Budapest, then became director of the Dresden Opera, and an authority on Wagner, Richard Strauss, and his own favorite, Mozart. But in the U.S., where...