Musical vandalism, or more simply, The Clap.

As some of you will know, I am extremely exercised by one of the most howling examples of poor concert etiquette yet inflicted, in which the cosmic conclusion to Karlheinz Stockhausen's "Kontakte" was destroyed by a lone imbecile intent on including themselves in the proceedings. I am writing about this in an effort to reach out to this person, and anyone else of a like-mind, as I believe they need some help. However, I want to start this essay by recalling another event, and one in which dear Karlheinz was also a victim. In 2008, the BBC Proms presented a portrait concert of this legend, one in which we heard a whole evening-long festival of his music. Love or loathe, he is a unique maverick figure of huge artistic character, and of enormous influence. On this occasion I was performing "Kontakte" for the first time and the BBC Symphony was playing "Gruppen" - twice as it tuned out (the more the merrier). I sat in the auditorium, keen as mustard to hear this astonishing work in concert, one which only truly comes to life effectively when heard so. It was marvellous! It was shocking. It was...witty! It was beautiful, it was un-nerving. And then, incredible as it is to report, NO SOONER had the last note rang, than a lone idiot chimed in with a rather buffoon-some applause, dragging three thousand wary followers with them, nearly all of whom I suspect would have appreciated even just a couple more seconds to digest, with the requisite respect, the final resonance in the Albert Hall of this astonishing experience. I was dumbfounded, and had to conclude that this was not innocent, and that the person in question somehow wanted to stamp their vastly authoritative knowledge of the coda of this work onto the proceedings. And in so doing, hijacking the event for their own petty means.

Mercifully on this occasion, we were spared the same indignity for the "Kontakte" performance. The piece ends with an indescribably effective sonic winding down, in which the final gestures of the instrumentalists are delicately, vulnerably, paired to the retreating tape part, as the whole musical continuum gaspingly evaporates. You are left frozen in magic. To live these moments collectively, to fuse in this joint meditative state, is one of the deepest human experiences we can share.  On listening back to the broadcast, I was curious to see how long that silent reflection lasted. 90 seconds.

October 2013. Stockhausen has now been dead for nearly six years. My privilege is to serve, once again, the great "Kontakte" in performance. South Bank Centre. "The Rest is Noise". Queen Elizabeth Hall. Sold out. Expectant crowd, buzzing musicians backstage. The work gets underway. We chime, we hurl, we do battle, we reach out, we reach in. We give all that we have to this music, the better we play it, the more we get to know it, the more wildly mysterious it seems. The conclusion begins, the sounds become fragile, we are lifted into an out-of-body state. Music's spell cast. But then. Oh no. Oh please no. Not that person....again?? Yes - but worse.

As I lift, for the last time, my brush to make the final contact (the clue's in the title, you moron, yes you) with the vanishing-but-not-out-yet tape part, a pathetic, wizened clap is launched into the atmosphere. We are not even DONE here yet, people! I shoot a withering stare (one that would have stripped paint, I'm told) in that direction, desperate to save the situation and dissuade further disturbances. But no. They try again. And with incredulous reluctance, people, freshly jolted from their reverie join in piecemeal.

I'm not asking for the world here. I really don't think I am. I would merely like to suggest some manners, no different to those used by anyone out there who wouldn't walk in front of someone engaged with a painting in an art gallery, or emit a loud noise during the crucial speech in a play. Music needs a certain environment and respect to have full effect. And no - that is not, not, elitist.

I love applause. It can be wherever it likes if it is in passionate and logical reaction to something incredible and if it disturbs not. When I play the Jennifer Higdon concerto, and the brain-melting cadenza finally reaches its epic, thudding conclusion, there is often a spattering of applause, and we are two or three minutes from the end of the work. Anyone who has seen or heard this will have noted my on-stage reaction. The world's biggest grin combined with a huge thumbs-up!! Thank you, truly, for engaging so well with the music!!! You have understood it and your reaction is welcome, encouraged. See you at the next one, my friends!

For our repeat-offender from above, I realise my evidence is not complete, conjectural even, but I'm building my profile. That you hurt me and our audience on Saturday, that is unforgivable. I have spent my LIFE preparing these concerts, and in this case I have loved "Kontakte" since I was 12 years old and used the music for wallpaper in my bedroom. And as such, that you hurt this MUSIC...well.

There are no words left.