This young rising star from Philly just got the call-up of a lifetime

Kensho Watanabe can barely fathom the turn of events that found him on stage leading the Philadelphia Orchestra last weekend -- with three hours' notice.

"I know what happened," Watanabe said in an interview this week. "But my brain is still processing it."

Surreal is one word that comes to mind, he said. Watanabe was notified at 5 p.m. Saturday that music director Yannick Nézet-Séguin had come down with a virus and could not conduct the 8 p.m. program at the Kimmel Center.

But supported is another word, because he knew the players personally, having played in the orchestra as a substitute violinist, and, later, having passed the audition that landed him the assistant conductor position in fall 2016.

His biggest fans were there, too. "My parents were able to drive down from Greenwich, Conn. I called at 5:15 p.m., and they jumped in the car right then."

As assistant, Watanabe had attended all of Nézet-Séguin's rehearsals and had learned the pieces. By several accounts, his concert debut with the orchestra was better than good. In fact, the hall was reportedly electric.

"He was really poised ... to just drop in and be cool as a cucumber ... that's really special," said composer Mason Bates, who was on stage Saturday running the electronics for his piece Alternative Energy. "It was very impressive."

Born in Yokohama, Japan, and raised in the United States, the 29-year-old Watanabe attended the Juilliard School's precollege division as a violinist but entered Yale as a biology student. His grandfather had died of colon cancer, and he felt inspired to become a physician.

However, music won out, and before long, he was a conducting student at the Curtis Institute, working with  Otto-Werner Mueller and later with Nézet-Séguin. He graduated in 2015.

His Philadelphia Orchestra debut was meant to be a children's concert on April 22, which is still happening. He'll also conduct Puccini's rarely heard opera La Rondine April 27 and 29 in a Curtis Opera Theatre production at the Kimmel Center. We talked by phone Monday.

What went through your head in the hours leading up to the concert?

Just get it done. Then I thought, "You know the pieces. You're prepared. Let's make something out of this."

I never imagined at this point in my career that I would work with Daniil Trifonov. [The celebrated Russian pianist performed with the orchestra on the Saturday program.] I didn't think I would be on the same stage with him. That may have been the most challenging, just to make that partnership happen.

How much did knowing the orchestra help?

Everybody had my back. But nothing prepares you for a situation like Saturday. I hadn't conducted the orchestra since my audition.

When Leonard Bernstein made his famous last-minute New York Philharmonic debut in 1943, the ailing older conductor Bruno Walter called Bernstein to his bedside and gave him a few lifesaving pointers. What was the 21st-century version of that with Nézet-Séguin?

He texted me to ask if there was anything that I needed. I had one question about Mason's piece, about the electronics, and he was very happy to provide that. And he was sending me good vibes.

You started playing violin at age 2. Do you even remember that period? And when did conducting enter the picture?

I have a distinct memory of performing at age 4 or 5, and just keeping my violin held up. Conducting was not my interest growing up. I didn't want to enter a conservatory. I wanted to go to a school with good academics as well as music, and Yale seemed like the best way to go.

I fell into conducting an ensemble that needed a conductor, and then I became assistant conductor of the Yale Symphony. And I was all scienced-out.

What's your life like when you're not making music?

I'm going to a Phillies-Mets game tonight. I'm a big New York Mets fan. I played a lot of baseball growing up. I love hockey, as well, but once when somebody skated over the top of my finger, my mom said, "Enough of that."

What video games do you play?
League of Legends. I like to play games because you have to think about many things at once and anticipate certain things to happen. This is very useful in terms of conducting, where I have to keep track of many things at once. I don't believe that I'm talking about this with you.

Do you miss playing with the orchestra as a violinist?

I'd love to go back and do that at some point. Technically, I'm still on the substitute violinist list. But I can't play in rehearsals when I'm expected to be in the hall listening. Maybe on tour when somebody gets sick.

After your Saturday debut, were you ready to step in on Sunday if Nézet-Séguin was still ill?

I was ready. But he felt well enough. We did have a stool out for him on the podium in case he needed to sit. But he was fine.