You were appointed concertmaster at the Concertgebouw aged 18. What were the challenges of taking on that role so young?

When you are very young, you can make an enormous number of mistakes. At that age you are supposed to start to go out with girls, and have a great time with friends. But I came to an orchestra with years of tradition who play, week in week out, with only the greatest conductors. That was a youth’s adventure for me! A big step, but an incredible school at the same time. One of the challenges was that I needed to really learn the repertoire – and every week. It was a big challenge.

How did your violin career help prepare you for a career in conducting?

The strange thing is I did not prepare at all as a conductor in those years. It was only when Bernstein asked me to come in front of an orchestra. He was conducting the Concertgebouw and he wanted me to do some of Mahler One – the first movement – so he could go into the hall and listen to it. I said, “Lenny, I never conducted,” and he said, “just do it, just do...