“I’m aware I don’t really look like your standard conductor,” said Gemma New, 26, the associate conductor of the New Jersey Symphony Orchestra. “I look very young. Many people ask what college I’m in. But once they start to talk to me and see my work, I think their ideas are changed.”

In 2007, Marin Alsop, probably the most prominent female conductor in the world, became the music director of the Baltimore Symphony Orchestra, the first time a woman had led a major ensemble. (Her predecessor was none other than Mr. Temirkanov.) Looking back on her career in a phone interview from Brazil, where she is also music director of the São Paulo Symphony Orchestra, she said: “When I started, I kind of naturally assumed that there would be more and more women entering the field. But it was strange because the numbers didn’t really change 10 years down the line, 20 years down the line, even 30. The numbers hadn’t increased in the way I assumed they would.”

In certain ways, we are still living in the old world. The enterprising Antonia Brico was supposed to have made her Met debut back in the 1930s. But the popular baritone John Charles Thomas declared that he would never perform under a woman’s baton, and that was that. The conductor Anne Manson said, “There was one conversation my agent had with one of the opera companies in Britain and they said, ‘We could never put a woman in front of this orchestra.’ I believe the quote was ‘She’d get eaten alive.’ ” Another American conductor, Laura Jackson, said that in the early 1990s, she was told by a female official of an orchestra in New England that “we don’t do women conductors here.”

It took until 1976, decades after Brico was denied, for the barrier to be broken at the Met by the formidable stage director, impresario and conductor Sarah Caldwell, and she was tapped only at the insistence of a star singer, Beverly Sills. Simone Young followed in 1996.