Ever since I first worked it out, it has seemed more than coincidence was at work in the fact that Xenakis, Ligeti and Dumitrescu all have their roots in a single country, Romania. How comes three of the most profound composers of the last century shared this history? And how might their circumstances have affected their work?

Why Romania in particular should be implicated I can't yet say, though I am keen to find out, but it seems to me that, certainly in the case of Ligeti and Dumitrescu, one factor might be that the very repression and conformity promoted by the Communist Parties had a paradoxically beneficial effect.

The background to the story is the All Union Congress of Composers held in Moscow in 1948, which endorsed the policies of Andrei Zhdanov, introducing bizarre criteria of what music would be politically acceptable. All this was carried through by loyal party hacks such as Hans Eisler. Ligeti's Romanian Concerto was banned by party apparatchiks simply because it has a passage where an F sharp is heard in the context of F major: one of the guiding principles of Communist stupidity in art was that socialist art would reject dissonance and conflict, reflecting the official lie that dissonance and conflict had been abolished in society. This led them even to condemn the music of village bands as not being 'real' folk music because it too was dissonant. Under Communism music had to be formally uncontroversial, easily comprehended and speaking with 'the voice of the people'. As 'the people' had effectively been demoralised, disorganised and dispersed to be replaced by atomised slaves of the state, what this meant in reality was that art should unambiguously reflect the needs of the ruling party at any moment.

As part of the same mechanisms of control, the 'degenerate art' of the west (they used exactly the same terms as the Nazis to describe modern art) had to be expunged, banned and embargoed, making it very difficult for radical composers in the east to connect with the details of the modernist tradition. Instead, crucially, they had to connect with it largely through their imagination.

Ligeti's wife managed to get a copy of Adorno's 'Philosophy of Modern Music', which helped give him the confidence to develop new ideas about his radically dissonant and chromatic 'black music'. But once the impetus was received he had to develop the resulting music in private and largely in secret. Dumitrescu too talks of how, being cut off from the western music practically, he connected to it in his imagination, attempting in private to keep up with the tremendous pace of change he imagined taking place without him in London, Paris and New York. In a strange way, their very isolation led them to make even more astounding leaps into the unknown.

Ligeti comments on how odd he used to find it when people asked him who he wrote his music for - as his music was unplayed and unplayable in his own country, he didn't write it for anyone but himself. This very isolation, though, meant that he was relieved the burden of having to cater to any particular audience, and this too surely helped him to move further on in his ideas and investigations.

In its own way, the extent of Stalinist repression in art undermined itself. Not flexible enough to incorporate and occupy their enemy, the Stalinists left them alone to plot and plan their schemes for the total renovation of music. To that extent we can might even be grateful to the bureaucrat, Zhdanov, for indirectly feeding these ambitions. The triumph of the new music over the bureaucratic ideals of 'proletarian culture' or 'socialist realism' is part of the 'revenge of history' which Trotsky always claimed was 'greater than the revenge of the Party Secretary'.