This post starts with the kindness of a stranger.

When I was chasing up the story of the 2009 BBC Jazz Awards last week, a Radio 3 publicist called Victoria, quite unexpectedly, lobbed a generous invitation at me, to attend a “Total Immersion Day” on Iannis Xenakis at the Barbican. Nice one. Go with the flow, I thought, and accepted it.

So, there I was, at ten o’clock on a Saturday morning stepping into the Barbican. This is very familiar territory, from several years of taking sons to the excellent children’s library when they were small. Others may suffer from Barbicanophobia. I don’t, and I believe it’s almost certainly treatable for those that do.

As I arrived, I realised I was in for quite a surprise. Rather than the scattering of families I remember from the old days, the place was absolutely heaving with parents and young children, attending what seemed to be a very successful “Do Something Different” day. Staff with orange badges and walkie-talkies in a hurry, criss-crossing. It looked like a lot of fun was going to be had.

But a Press Pass instils a sense of purpose in me. And that purpose was to join the adults (a lot of people wearing black…) getting to know the uncompromising Paris-based Greek composer Iannis Xenakis (1922-2001), associate of Le Corbusier, a man with serious inner demons, addicted to complexity, a composer dead set on unravelling the mysteries of the universe and of himself through mathematics. I remember him as a darling of IRCAM and of the trendy Nouvel Obs in the days when I was a Paris student with serious- OK, ludicrous- seventies sideburns.

First up at 10.30 was a talk by Ivan Hewett of the Daily Telegraph. Hewett was also responsible for just about all of the content of the excellent programme book. If I can borrow the assessment terminology which the Royal Academy of Music jazz professors use to describe their very best students: Hewett has his sh*t completely together.

A couple of brief descriptions of Xenakis which Hewett quoted:

“The prophet of insensitivity” Milan Kundera.
“Wonderful mind. No ears.” Pierre Boulez.

I learnt that Xenakis decided in 1957 to make the permanent shift from working in Le Corbusier’s architectural studio into music. Why? Because he had fallen out with Le Corbusier. And what had originally driven him to compose? Because he was in a depressive state and only through music he could deal with “what was fundamental” to him.

The film had a nice clip of Xenakis’ widow Francoise talking to camera. Poor, loyal Francoise had tried for decades to explain to her husband that, as a French woman, the distinction between beauty and ugliness actually meant quite a lot to her. How, she begged him to explain, could it be so irrelevant to him?

“Ca ne fait rien. Tu es bete.” (It doesn’t matter. You’re stupid.)

How did twentieth century classical composers get away it? How were they given the right to be implacable and angry through music? Who told them that their duty, their God-like role in society was to obey their demons, to live on the edge, and to cast away all norms of humanity, beauty and responsibility? Don’t we all have an inner angry Xenakis within us that we try never to show the world. I have…and I don’t always succed in hiding him. I would not recommend to anyone, least of all myself, to spend a “total immersion day” with my inner Xenakis.

Wayne Shorter deals with issues in music and in life at least as weighty as Xenakis, and writes music which I am sure will prove more durable. Read the letter he wrote for Joe Zawinul’s funeral.

I carried these thoughts into the first concert, by the Guildhall Percussion Ensemble.

If the classical composer is permitted to function as a savant child, what licence do the mere performers get in this music? The answer is not a lot. They are expected to be totally submissive to the composer’s will. And the expressions on the Guildhall students’ faces seemed to suggest exactly that. One over-arching duty for the performer: not to get a single note of this fiendish stuff wrong.

As I watched three Guildhall percussionists on Djembes I was thinking: yeah, sure, they’re OK, but perhaps there is something more elemental in this music, which needs a different gear. And people around me are reading the programme. I’ve heard hand drums played in the last few months by Asaf Sirkis, by Paul Clarvis, by Dave Smith, mostly at the Vortex. If you want an extreme composer’s vision brought to life, if you want your audience to stop reading the programme, and to cheer rather than be respectful, just bring on these guys.

The jazz musician is both composer/creator and interpreter. The performing voice is formed through performance (how else?). And if your inner voice is telling you to create and to interpret and to perform simultaneously, then the bar is inevitably set higher for you as a musician than it ever was for a Xenakis.

I couldn’t attend the main event of the evening, a BBC Symphony Orchestra concert. I regret that, because I know that if any orchestra in the world can do justice to the IRCAM school, it is the BBCSO.