The most recent broadcast, of Donizetti’s “Lucia di Lammermoor,” starring Anna Netrebko, was seen in 31 countries in roughly 850 theaters. The Met is even negotiating to send an opera feed to an Argentine base in Antarctica. “Seen by an audience of penguins,” Mr. Gelb joked.

The phenomenon has its technological handmaidens: DVDs, online streaming, downloading and satellite radio broadcasts, all part of the digital forces that have come to shape the classical music world in the last five years.

The HD transmissions are one of the few bright spots for the Met, which is facing an economic crisis on just about all fronts because of the recession. The program has brought the company attention and a modest income stream: about $1 million netted this season, not much for a $271 million budget, but something. Much of that money comes from ancillary sales based on the transmissions.

The HD program forms the core of a strategy devised by Mr. Gelb, when he assumed control three seasons ago, to boost the Met’s profile in popular culture and build new audiences.

“I don’t think anyone, including myself, expected it to be quite as successful as it is,” he said. But even in this area there are signs of cutting back. The Met said last week that after three years of increased transmissions, it would transmit only nine operas next season, although it declined to call this a cutback because a 10th transmission could be added; an 11th was added at the last minute this season.

Mr. Gelb said the program’s success has made the Met more attractive to opera stars craving larger audiences, the international spotlight and maybe the applause of penguins. The transmissions, he added, are also largely responsible for a 12 percent growth in ticket sales at the opera house since he took over, although he acknowledged there was no hard evidence for this.