1877 was a year of crisis for Tchaikovsky, for in this year he entered into two remarkable relationships with women. One sustained him physically and spiritually for many years to come, while the other came to a swift and catastrophic conclusion.

The first relationship was with Nadezhda von Meck. She was 45 years old, and had been married to an energetic and successful railway engineer. His death in 1876 left her a widow with a large fortune and a passion for Tchaikovsky's music. She and Tchaikovsky only ever communicated by letter and, despite occasional encounters in the Street or at a theatre, they never once talked face to face. Their constant correspondence - an average of two letters per week for more than ten years - was an emotional release for both of them, and Mrs. Von Meck's considerable financial support of Tchaikovsky was crucial to him.

The other relationship was Tchaikovsky's disastrous marriage to a young student and admirer called Antonia. There must be many reasons why Tchaikovsky drifted into this loveless relationship, despite (or because of?) his homosexuality, including feelings of sympathy and guilt, and a desire to convince himself he could have a "normal" relationship. The result - immediate separation, attempted suicide and a nervous breakdown - proved to himself as well as his colleagues and public, that he could do no such thing.

The sketches for the fourth symphony were written early in 1877 and in July 1877 he agreed to dedicate the symphony to Mrs. Von Meck, in the phrase "to my best friend". Later the same month he married Antonia. The next 10 weeks were a personal hell for Tchaikovsky, and after attempting suicide by immersing himself in a river, he fled to St.Petersburg and then Venice. Once away from Moscow and from Antonia, he began to recover, and by December was able to continue work on the symphony. He worked hard on the orchestration over Christmas, and by mid January it was finished. The first performance took place in Moscow on 10th February 1878. Unfortunately the performance was a poor one, being ill-prepared in the time available, and made little impression. The first performance in St. Petersburg later that year went much better, and the critics and audience were unanimous in their enthusiasm.

The opening fanfare represents fate, "overpowering and invincible, against which there is nothing to do but submit". The first theme of the allegro is a long, sinuous melody that couples an ability to change shape with a complete inability to escape from its hypnotic waltz rhythm. After a while, a gentler second theme appears; a lilting dance on clarinet, with drooping phrases from the other wind instruments. This develops into two other themes - the first, gently rocking is first heard on cellos, while the second is bold and assertive. A climax is interrupted by the fate motive, which heralds a short but complex development of several of these themes. A respite is provided by the dancing second theme, but the following climax is once more interrupted by fate. This time it is followed by an accelerating coda, which drives to a tempestuous conclusion.

The other movements are more straightforward. The second movement comprises a very beautiful and seemingly endless melody which begins on the oboe, is passed to cellos, is taken further by the full strings and then varied by the bassoons. A central section is faster, and works up quite passionately, before the original theme returns, this time decorated with drooping woodwind phrases from the first movement. The bassoon has the last word.

The scherzo is a remarkable invention. The strings are pizzicato throughout, while a central episode alternates wind and brass in a skittish theme, with brilliant piccolo flourishes.

The finale, which enters with a crash, is mostly fast and furious, with a contrasting second subject closely modelled on a Russian folk song. In developing these ideas, the folk song becomes full of the sound and fury of the main theme, until the whole flow is stopped in its tracks one last time by fate. But the flow this time is unstoppable: the music regains momentum and whirls to a triumphant conclusion.