"What was amazing is that the audience was completely different from the normal orchestral one. The Barbican was completely sold out, with most people between the ages of 16 and 30, and they were completely with us."
Back in Auckland, video games are forgotten as he prepares for Thursday's concert of Martinu and Korngold, with Russian pianist Nikolai Demidenko as soloist for Rachmaninov's popular Piano Concerto No2. A recent German tour with Demidenko, playing Rachmaninov's Third Concerto, filled Stier with new admiration.
"Nikolai played that concerto six times over eight days and it was always fresh. He's so faithful to the score and will pull you up if you make even the slightest deviation. And he's always really honest.
"Demidenko's not the sort of artist interested in promoting himself - he promotes the music."
Erich Wolfgang Korngold is a composer you may have heard producing post-Straussian musical wallpaper behind Bette Davis and Errol Flynn in Hollywood's heyday. Movies such as The Adventures of Robin Hood and The Private Lives of Elizabeth and Essex would be unthinkable without his surging scores.
The Austrian's 1954 Symphony, which receives its New Zealand premiere on Thursday, was a contentious piece for its time. Korngold stated that this work would "show the world that the use of atonality and ugly dissonance - at the expense of inspiration, form, expression, melody and beauty - will result in ultimate disaster for the art of music".
Stier laughs at the quote, but defends Korngold's seriousness and sincerity. "My first exciting moment was with the third movement, which is like a great funeral march. That touched my romantic soul."
The conductor is quick to defend any accusations that the 48-minute work is the holiday project of a retired movie composer.
"Korngold's Violin Concerto may be sentimental Hollywood music but the symphony is altogether different," he stresses. "It can be a little like movie music, but then it can also be sarcastic, harsh and brutal, at times really funny.
"The whole piece may be 10 minutes too long, but I won't be making any cuts."
It is all part of the challenge of being a conductor. "The structure and direction of Korngold's music is not always easy. It's incessantly going up and down, up and down, and, just when you're expecting it to finish, there's yet another climax. But that's my job - to make it listenable."