Voigt, one of the world's leading singers of Strauss, made headlines last year when the Royal Opera fired her from a production of the composer's Ariadne auf Naxos because the director wanted his Ariadne to wear a slinky black dress. But before that public humiliation, she told the Times, she was concerned about her health and had already decided to undergo the procedure, in which the capacity of the stomach is reduced. She had the surgery on June 7 in New York, and has since lost 100 pounds.

There were professional risks to the operation: Losing weight can reduce the impact of a powerful voice like Voigt's. In addition, she said, she worried that the insertion of a breathing tube during the procedure could damage her vocal cords.

Voigt has had to change her technique as she has gotten smaller, she told the paper. "The sort of automatic engagement of the abdominal musicles from the excess weight doesn't happen anymore," she said. But both she and critics have been pleased with the sound of her voice in recent months. She added that she is being offered more chances to sing certain roles, including the title role of Puccini's Tosca.