And the timing is perfect. Just as the opera house was facing severe financial difficulties, along comes the Texas socialite and Met Opera board member, Mercedes Bass, with the fat envelope. Better still, it is not a pledge to give money, but cash that is on the table now.

"The Met's angel has shown her face," said Joseph Volpe, who will be retiring as the company's general manager at the end of this season after 16 years. "I think it's wonderful. In many ways, it kind of caps a wonderful career that I've had."

Ms Bass, a fixture on the Manhattan social scene, is married to Sid Bass, the Texas energy billionaire and philanthropist. As is the tradition, the couple can at least expect to see their name on a plaque on the Grand Tier at the Met's Lincoln Centre home.

"The important thing is not so much having one's name on the Grand Tier, but to help the Met," Ms Bass told The New York Times. "I'm a complete opera lover."