FRANKFURT (AFP) ― Mobile phones are frequently regarded as the bane of classical music concerts, especially when they go off mid-performance.

But it wasn’t a jarring ring that shattered the concentration of Polish pianist Krystian Zimerman during a recital Monday in the German city of Essen.

Rather, the 56-year-old stormed off when he noticed an audience member filming the concert with a smartphone, organisers told AFP.

Zimerman, renowned for his perfectionism and regarded by many as one of the greatest pianists of his generation, was giving a rare solo recital of works by Debussy, Brahms and Szymanowski in Essen’s Philharmonic Hall as part of the prestigious Ruhr Piano Festival.

“He noticed someone up in the choir seats filming the concert on their smartphone. We think it was probably an iPhone,” said festival spokeswoman Anke Demirsoy.

“He asked them to stop, but they didn’t. So he interrupted the recital and walked off stage,” she said.

When Zimerman returned a couple of minutes later, he apologised to the rest of the audience, explaining that he had previously lost recording contracts because of illegal videos of his performances uploaded onto Internet platforms such as YouTube, the spokeswoman said.

“Record companies would say, ‘Sorry. But this is already on YouTube,’” she quoted Zimerman as saying.

“YouTube is destroying music,” he reportedly protested, before resuming the concert.

Demirsoy said the culprit could not be apprehended afterwards.

Essen’s Philharmonic Hall, like most concert halls around the world, has a strict ban on making sound and video recordings during concerts, but such restrictions are difficult to enforce.