Love letters by the score

Musicologists have uncovered the erotic secrets of Berg's Violin Concerto, hidden in complex codes. Michael Church on how the puzzle was solved

One of the questions that would-be code-breakers were asked by the War Office in 1940 was: "Can you read an orchestral score?" That is a perfect illustration of music's linguistic power both to reveal and to conceal. Ever since Pythagoras discovered that the sweetest harmonies were governed by the simplest mathematics, number has been regarded as this language's foundation. And gradually, musical numerology acquired religious significance.

In Bach's day, pieces of music governed by the number three, 12 or 33 were assumed to reflect, respectively, the Trinity, the Disciples and the years of Christ's life. Viennese Masons could read their own numerical messages in Mozart's Magic Flute. In some hands the game got terribly complicated, but it was often as simple as ABC.

ABC? Yes, indeed: when the notes of the diatonic scale were given letters, the result was a proliferation of codes. "Every Good Boy Deserves Favour" was how young pianists were once taught to memorise the lines of the upper stave, EGBDF - hence the title for the anti-Soviet music drama Tom Stoppard wrote in the Seventies.

But what about BACH? No problem. Bach himself composed pieces based on the theme created by his name, as did Beethoven and Liszt in homage to him. (In German notation, A stands for A flat, and what we call B, they call H.) Smetana and Shostakovich were among many composers who wrote their own ingenious signature tunes. Our own Edward Elgar was a skilled cryptologist: his Enigma Variations live up to their name.

The beauty of musical codes is that they can also convey jokes. The Irish composer John Field once sent two grateful melodies to a hostess after a nocturnal feast, the first spelling out BEEF, and the second CABBAGE. And ciphers have often been used for more intimate purposes, as in Brahms's musical love letters, and Schumann's white-hot anagrammatic wooing of his pianist child bride, Clara. But the release on CD of the definitive version of Alban Berg's Violin Concerto allows us to savour a uniquely convoluted and fateful musical mystery: no composer was more code-crazy than this fastidious Viennese, or more desperately driven to cover his tracks.

Berg, the composer of Lulu and Wozzeck, was among the founders of modernism, along with Anton Webern and his hero Arnold Schoenberg. He shared all the intellectual enthusiasms of his day, including the prevailing fads for astrology and the occult. Dandyish and Wildean, he suffered from a weak heart and was prone to irrational anxieties - he had a horror of trains and a childish fear of thunderstorms.

He also had a penchant for turning superstition into reality, with ultimately fatal results. That took root when Berg's father died prematurely: as a result of the shock, the 14-year-old Berg suffered the first of the asthma attacks that would plague him for the rest of his life. The attack happened on 23 July 1900. From then on, the number 23 became an obsession, one of its many manifestations being his need to finish every composition on the 23rd day of the month. He persuaded a journalist friend to found a paper entitled 23 - A Viennese Music Journal, in which he fought battles on behalf of Schoenberg. He looked for the numbers on postmarks and tram tickets, and went through extraordinary mathematical convolutions to convince himself that the number - or a multiple of it - was there. (Oddly, other Viennese, including Freud, also regarded 23 as significant, though not with Berg's manic intensity.) The composer's early death at 50 came as a result of blood poisoning after an insect sting on the base of his spine. As he lay in hospital, he calmly remarked: "Today is the 23rd. It will be a decisive day." It was indeed: within a few hours he was dead.

That was in 1935. He did not live to hear the Violin Concerto - his final work - performed, but he let it be known that he had written it as a requiem for a friend's much-loved child. Manon Gropius, the daughter of Alma Mahler and the architect Walter Gropius, had died at 18 from infantile paralysis. The first part of the work depicted her in life and health; the second, in sickness and death. Berg's manuscript is annotated with "cries" and "groans" of instrumental grief. The chord at the climax of the opening of part two is labelled "Lahmungsakkord" - Kinderlahmung being the German name for the illness that carried her off. It all seemed perfectly clear.

But it wasn't. Musicologists began to realise that Berg's fateful number 23 was much in evidence in the structure of the work, and that it was often coupled with another number: 10. Sleuthing revealed that to be Berg's symbolic number for a woman named Hanna Fuchs, with whom he had fallen adulterously in love. Berg's widow Helene - who also believed in the occult, and would commune with her dead husband through table-tapping - strove for the rest of her long life to erase all mention of the affair, blacking out page after page of his diaries and forbidding anyone to inspect any score that might give the game away. Only after Helene's death was it discovered that Berg had used musical codes and directions to chart the progress - in terms that only Fuchs would understand - of the illicit love. In his celebrated Lyric Suite, those directions are almost risibly transparent - "Trio estatico", "Presto delirando" - but in the concerto the amorous secret is expressed in number games of mind-boggling complexity.

Led by the British musicologist Douglas Jarman, the search for Berg's extramusical messages has shown that behind the games lay a further amorous secret. Intertwined with the chorale that ends the work is a jaunty Carinthian folk melody whose words (though not sung here) tell of a night of passion with a young lady named Mizzi. And, yes, that turned out to be the name of a Carinthian girl by whom Berg had an illicit daughter while still in his teens. A photograph of the daughter, looking fetching in a sailor suit, was found, and on it there was an elegant inscription by Berg: "Let it be known that I am the father. I shall never shirk the resulting responsibilities." This, then, was another of his dying musical thoughts.

So is that it? I fear not. The diligent Jarman has also unpicked a political message - again, labyrinthinely expressed - which he interprets as Berg's rejection of the culture favoured by the Nazis. Berg wasn't Jewish, but his music was tarred with the "cultural Bolshevism" brush used to banish all artistic modernism from the German-speaking world. This particular message is expressed via a mysterious cluster of Fs, which denote the motto of a leading fascist youth movement.

Jarman is working on a definitive edition of all Berg's music, and in the case of the Violin Concerto that has meant correcting so many copyist's mistakes that only now can the piece be seen as the composer intended. Yet the odd thing is that the work has a marvellous emotional directness, despite all the subterfuge and cleverness that went into it. How much do these messages matter to listeners now?

Daniel Hope, the violinist whose tenacity helped to push the new recording into production, is in no doubt. "It's good for an audience to hear a piece the way the composer wrote it. They won't understand all the codes, or every intricacy of his 12-note system, but they'll get a lot, and that will enrich their appreciation. When I play the piece, I have all the codes marked in yellow. I first heard it when I was 14, and it blew my mind." The way he plays it on this CD suggests that that's still the case.

'Berg & Britten Violin Concertos': Daniel Hope, with the BBC SO/Paul Watkins, is released by Warner Classics