Conductor Antonio Pappano, on Top and Learning on the Job

It was just a few hours before a concert, and the London Symphony Orchestra was only now rehearsing with its star soloist.

Janine Jansen, the violinist featured in Bernstein’s “Serenade (After Plato’s Symposium),” was supposed to have performed the piece with the orchestra on its home turf in early February. But illness forced her to cancel, so she didn’t get together with the orchestra until the sound check for its first stop on its North American tour, at the Granada Theater in Santa Barbara, Calif., last week.

The conductor Antonio Pappano walked onto the stage with Jansen, then cued her to begin. To an average listener, what followed would have sounded like a pretty good performance. But to Pappano, there was work to be done.

“We can do better,” he told the musicians. “I’m sure.”

Concise in his directions and quick to compliment a success, he refined dynamics, asking the violins for a velvety glow, and demanded precision, telling the players: “You’ve got to be exactly with me or exactly with her. There’s no other choice.”

Eventually, Pappano was satisfied. He might not have had the luxury of an earlier performance, but “Serenade” was now ready for the London Symphony’s tour, which concludes at Carnegie Hall on March 5 and 6.

The Carnegie concerts will be Pappano’s first appearance with the London Symphony in New York since becoming the orchestra’s chief conductor last year. And they will be something of a homecoming for Pappano, who cut his teeth in Manhattan as a humble rehearsal pianist before rising to the top of his field, conducting at the coronation of King Charles III and receiving knighthoods in England and Italy.