For the first time in four decades, the Metropolitan Opera has a new music director. The company announced on Thursday that it was passing the baton long held by James Levine to Yannick Nézet-Séguin, music director of the Philadelphia Orchestra, known for vital, visceral music making.

The generational shift to Mr. Nézet-Séguin, 41, from Mr. Levine, 72, who stepped down last month after years of uncertainty and cancellations because of health problems, comes at a challenging time for the Met, the nation’s largest performing arts institution — and for opera.

While the company had a number of artistic successes this season and enjoys a broad global reputation thanks to its high-definition cinema simulcasts, it is facing financial hurdles that have forced it to make cuts in its $300 million budget and wrest concessions from its union workers. This season it filled only 72 percent of its seats, on average.

The energetic, media-savvy Mr. Nézet-Séguin is meant as a shot in the arm for an organization struggling at the box office and whose musical leadership has been in flux. As Mr. Levine has ailed in recent years, Peter Gelb, who had already assumed more artistic control when he became the Met’s general manager, took on an even greater role in choosing repertoire and artists.