I take a cassette out of a cupboard and go to the only machine I have left that can still play it. The technology feels old, for the cassette is a copy of a tape-recording made in 1968, of WH Auden reading his poems from a pulpit in Great St Mary's Church, Cambridge. Auden's reputation at that time was by no means at its height, but the church was packed with 2,000 attentive listeners. People were turned away, and the doors, alarmingly, were locked against them. The priest introducing Auden was Hugh Montefiore, and it was he who made the excellent recording, astonished at the amount of gin Auden had drunk before the reading (it doesn't show at all) and astonished that he recited all his poems from memory, something Auden liked to do.

A couple of years earlier, towards the end of 1966, I first met Auden and heard him read, also, as it happens, in a church. It was in a suburb of Burton-on-Trent, where his grandfather had been the first vicar. That elaborate Victorian church - St John the Divine, Horninglow - was celebrating its centenary. I remember Auden placing his books and typescripts a little way away from where he stood at the chancel steps, and reciting in exactly the unique accent that I can now hear again on the Cambridge tape, the accent that infuriated many of his contemporaries because it had assimilated the flattened a's of America. This forced the listener to remember that Auden, at the end of the 1930s, had emigrated to the States (from the late fifties he called Austria his home) and thus that he was no longer British. And this emigration still seemed to many a betrayal.

Another characteristic of Auden's recital style was its deflating manner. He loathed anything that smacked to him of self-aggrandisement in a writer and condemned poets who "to wow an audience utter some resonant lie". This connected in his mind with an abuse of political power, something he castigated when he recognised it in his past self. He associated it with fascism and the manipulation of the crowd. WD Snodgrass, a wonderful poet who is always an exuberant performer on the podium, was dismayed one year in Edinburgh to be given a fearful ticking off by Auden for the manner of his reading.

Auden was harsh on what he considered attention-seeking. Once when a friend referred to a public occasion when Robert Frost had forgotten his lines, Auden was satirical: Frost hadn't forgotten his lines - he was just trying to steal the scene. Auden said to me, "If you've only just written a poem, you don't forget the lines." (I don't think this remark was necessarily fair. It sometimes takes a little time, even if you are a poet who can remember his poems, to forget some previous versions or cancelled words.)

The 1960s was a period when writers in the west began to be aware of the extraordinary eloquence and popular attraction of the Russian poets such as Yevtushenko and Voznesensky - oppositional figures who could draw crowds. The Russian poets recited from memory as a matter of course. Auden translated some Voznesensky, but he would have died rather than recite one of his own poems in the vatic manner that I once heard Voznesensky recite "I am Goya". And he would never have become a mouthpiece for Gorbachev and perestroika, which is what Voznesensky became.

Auden knew he had the power, should he care to use it, to whip up an audience, so he went a long way in the opposite direction, presenting his lines in a matter-of-fact voice. But he was also a keen shocker of bourgeois sensibilities. Indeed, his anti-poetic manner was a way of shocking. When a lover once complained to him that, for a poet, he was not very romantic, Auden replied: "If it's romance you're looking for, go fuck a journalist." In the reading at Great St Mary's, he used the F-word from the pulpit - a fact that was noted in the press. (It occurs at the end of "Song of the Devil", so Auden was well within his rights; but he would have known perfectly well what he was doing.)

The day after the Burton reading, Auden came to my school nearby and spoke to a small group of us. He was connected to this school, Repton, in various ways, the best known of which was through his friend and sometime lover Christopher Isherwood, who remembers it in Lions and Shadows. Auden's father, GA Auden, had also been there, and the school possessed some of his inscribed copies of his son's poems, which in those days we could find on the library's open shelves. I remember being baffled and thrilled reading a first edition of The Orators. But I didn't then know who GA Auden was.

The parish church of Repton, with its distinctive thin spire and its Anglo-Saxon crypt, was named after St Wystan, a fact that had struck some of us boys, and a few months before we had celebrated St Wystan's day with a reading of Auden's poems in the churchyard. We had written to Auden about this, and he had been touched. In his reply to me he used a word I had never heard before: he thanked us for celebrating his onomastiko, his name-day.

Actually meeting Auden was an experience that left us quite out of our depth, and there were awkward silences in our small group discussion. I remember desperately trying to think of questions. I asked him what he thought of the latest generation of poets - Ted Hughes, for instance. Brushing the inquiry aside, Auden paused for a moment before saying with a smile that he always suspected questions of that kind of having some malicious purpose. As soon as he said this I recognised with a blush that I had indeed been egging him on to say something perhaps disobliging about Hughes or his contemporaries, although I had no motive for doing so other than hero-worship. I must have crudely felt that, if Auden was the great poet of his day, he himself should say so.

On this occasion (and no doubt on others, for the elderly Auden often repeated his bons mots) Auden, when asked for his opinion of Yeats, said: "Yeats spent the first part of his life as a minor poet, and the second part writing major poems about what it had been like to be a minor poet." On another occasion Auden said that he had only once encountered pure evil in a person, and that was when he met Yeats.

If this comes as a surprise, considering that the most famous tribute to Yeats on his death is Auden's elegy, you have to remember that for Auden there was always a case pro and con, as far as Yeats was concerned. At the time I first met him, he had recently written to Stephen Spender (in a letter quoted by Richard Davenport-Hines in his biography of Auden): "[Yeats] has become for me a symbol of my own devil of inauthenticity, of everything I must try to eliminate from my own poetry, false emotion, inflated rhetoric, empty sonorities."

But as early as the year of Yeats's death, 1939, Auden had set out in the Partisan Review a marvellously trenchant pair of speeches for and against him, called "The Public v the Late Mr William Butler Yeats". You can find this essay in either The English Auden or the second volume of the collected prose. The first speaker is the Public Prosecutor. He tells us that Yeats had a feudal mentality, that he was prepared to admire the poor as long as they remained poor, and that "for the great struggle of our time to create a juster social order, he felt nothing but the hatred which is born of fear".

The Public Prosecutor is scathing about nationalism in general. "Of all the modes of self-evasion open to the well-to-do, Nationalism is the easiest and most dishonest. It allows to the unjust all the luxury of righteous indignation against injustice." He belittles Yeats's activities for a free Ireland: " ... if the deceased did give himself to this movement, he did so with singular moderation. After the rebellion of Easter Sunday 1916, he wrote a poem which has been called a masterpiece. It is. To succeed at such a time in writing a poem which could offend neither the Irish Republican nor the British Army was indeed a masterly achievement."

The Counsel for the Defence, however, has a reply to all this, and his reply has been left as the last word: "My learned friend has sneered at Irish Nationalism, but he knows as well as I do that Nationalism is a necessary stage towards Socialism. He has sneered at the deceased for not taking arms, as if shooting were the only honourable and useful form of social action. Has the Abbey Theatre done nothing for Ireland?"

At the climax of the speech, the Counsel for the Defence tells us that "art is a product of history, not a cause", and that "the case for the prosecution rests on the fallacious belief that art ever makes anything happen, whereas the honest truth, gentlemen, is that, if not a poem had been written, not a picture painted, not a bar of music composed, the history of man would be materially unchanged".

But there was one area in which the poet was indeed a man of action, and that was language. However false or undemocratic Yeats's ideas had been, his diction saved him in the defence's eyes: "The diction of 'The Winding Stair' is the diction of a just man, and it is for this reason that just men will always recognise the author as a master."

Upon this view of poetry and of art in general, formed in the latter part of the 1930s, Auden's reputation as the leader of his generation of poets had been wrecked, and he had wanted this wreckage to happen. He did not wish to be a leader - the German translation of the word will tell you why - in a world in which it could be argued (of Yeats) that "A great poet must give the right answers to the problems which perplex his age. The deceased gave the wrong answers. Therefore the deceased was not a great poet."

This judging of art by criteria of social utility, a pernicious commonplace in today's world (it was Stalinism's legacy to New Labour), was appalling to Auden. He had revised some of his works, and suppressed others, in order to purge them not only of the qualities he associated with bad Yeats - false emotion, inflated rhetoric, empty sonorities - but also of anything that smacked of subservience to the party line. When he spoke on public issues, it was as an individual conscience, not as a representative of a party interest.

But Auden never turned his back on the political world, and one of the things that strikes me, listening to the tape of the Cambridge reading, is how alive for him the recent past remained. He reads a poem in memory of Joseph Weinheber and, on introducing it, tells the audience that Weinheber was an important Austrian poet who was at first an enthusiastic Nazi supporter, but who gradually during the course of the second world war became disillusioned and depressed until, in 1945, he committed suicide.

There is a dialect phrase in the poem, which Auden has to explain. Weinheber had been taken up by the Nazis, and Goebbels had asked him what the party could do for Austrian culture. "In Ruah lossen," Weinheber's reply, means that they should leave it alone, leave it in peace - precisely what the Nazis were unprepared to do. What Auden is addressing here is the ghost of a man who had made a very big mistake (supporting Nazism) and died regretting it. His example is counterpoised against that of Franz Jägerstätter, a peasant from St Radegund in Upper Austria, a pacifist who "said his lonely Nein to the Aryan state" and ended up beheaded in Berlin. Auden wonders what Weinheber's heart, as an Austrian poet, would have told him had he known of this other man's example, but he adds: "Good care, of course, was taken / you should hear nothing ..."

What gripped me, listening to the poet's voice read this elegy for Weinheber, was Auden's aliveness to the history of Kirchstetten, the village where he lived in Austria and where I twice visited him, and to the brutality of its recent past. I had always thought of it more as a Horatian retreat from the city life in Manhattan (Auden in those days spent winters in New York and summers in Austria): a faintly perverse choice perhaps, but chosen for its moderate climate and its resemblance to England. Yet here in Kirchstetten he was also living among the ghosts of fascism:

Reaching my gate, a narrow

lane from the village

passes on into a wood:

when I walk that way

it seems befitting to stop

and look through the fence

of your garden where (under

the circs they had to)

they buried you like a loved

old family dog.

The tone of voice in the first stanza is deceiving, because it is not an old dog that is being buried but a suicide. Yet it is also appropriate, because Auden is not going to point a finger at Weinheber, but instead imagine him as someone with whom he might, in other circumstances, have become good friends. The abbreviation of circumstances to "circs" in the first stanza is typical of the linguistic mannerisms that used to annoy his critical readers, but Auden is expecting us to notice that the very informal language is gently referring to a terrifying moment in history.

But now I have to remind myself that the events Auden was recalling had taken place only 20 years previously, while here I am listening to his voice, to his poem, 40 years on. Auden's conversation, as opposed to his reading voice, has been preserved best by writers. Isherwood and Spender capture it in, respectively, the character of Weston in Lions and Shadows, and in World within World. But there are also two volumes devoted to his "Table Talk", one by Howard Griffin and the other by Alan Ansen, both of whom did secretarial work for Auden and took the opportunity to write down things he said (from recent memory). Griffin's is the more worked up volume, with quite long discussions of Shakespeare. Ansen's is the more gossipy and fragmentary, but I think a rather better likeness emerges.

The conversation jumps around: "The one good thing Galsworthy did was a play in which a character ate himself to death on the stage," says Auden, referring to something called Old English. The next sentence is: "Hamlet could never be put on the stage. I've seen the Stratford performance. Not very good. I think that the business about Hamlet's making the King drink the poisoned cup should be done slowly and brutally." You have to remember that Auden wouldn't have had the opportunity to see much good Shakespeare production.

Auden once said to me: "Every woman wants to play Hamlet, just as every man wants to play Lady Bracknell." He often talked about Wilde, and clearly thought a lot about his fate. Ansen records him asking: "Did you see The Importance of Being Earnest? It's an extraordinarily good play. It's about nothing at all, which is what makes it so good. Lady Windermere's Fan has some social references, which makes it not so good. But The Importance of Being Earnest isn't a bit dated. The trouble with Shaw's plays is that they're all brain and no body, which isn't good for the stage. There may not be any body in Earnest, but at least there are clothes. Obviously you have to see it - you can't just read it." And in the next sentence he tells us that "Lear won't do on the stage". And in the one after that: "Wilde, after all, isn't important as a writer - he couldn't write at all - but as a behaver."

Here is Auden, at tea, in company, in 1947. Someone asks him what he thinks of Robinson Jeffers. Auden: "I don't express myself on people who are still living. I only talk about people who've been dead a long time." A little later someone asks: "Why is your work so obscure while Spender's is so clear?" Auden: "I don't talk about things like that." What he means is that he will not be trapped into making invidious remarks about his contemporaries in public (exactly what I tried to get him to do 20 years later).

In private, it was a different matter. Here he is on Scott Fitzgerald: "I've been reading This Side of Paradise. Chester gave it to me. Those long conversations between the Princeton man and his girl. One simply can't believe that he cared for her in the least. All American writing gives the impression that Americans don't care for girls at all. What the American male really wants is two things: he wants to be blown by a stranger while reading a newspaper and he wants to be fucked by his buddy when he's drunk. Everything else is society." One hardly likes to question so definite an insight.

You may say that this kind of definiteness is just a verbal trick, or proceeds merely from a childish desire to shock. But even this bizarre view of American male sexuality turns out to be based on something, observations of sexual behaviour recorded elsewhere. An opinion that seems at first affected may turn out to have a great deal of thought behind it.

For instance, the idea that Lear won't do on stage was something that Auden did think, and that he argued in detail before an audience. Once again we are lucky that among those who attended Auden's Shakespeare lectures in New York in the 1940s were some assiduous note-takers, including Ansen. Arthur Kirsch managed to reconstruct these lectures in a splendid volume where we find that Auden believed the storm in Lear was not, as it were, a great big metaphor for what was going on in Lear's head. The storm was a storm, "without passion"; it paid no attention to the rights and wrongs of the play's plot. "A realism is required," said Auden, "which the stage cannot give. King Lear is the one play of Shakespeare that, in the storm scene, really requires the movies. Most movies of Shakespeare make you want to say, it's very nice, but why must people say anything? You want to see everything. If I agree with those who don't want to see King Lear on stage, it isn't because I don't think it's dramatic ..." It was because Auden thought that the important contrast was between what actually happened and what was being said. You may disagree with this, but Lear did eventually make at least one very good (Japanese) film.

Auden came very close to an ideal that eluded most poets in the 20th century: the revival of poetic drama. His ideas on drama were resonant: "Drama began as the act of the whole community. Ideally there would be no spectators. In practice every member of the audience should feel like an understudy." This ambition has been taken up by others. Auden continued: "Drama is essentially an art of the body. The basis of acting is acrobatics, dancing, and all forms of physical skill. The music hall, the Christmas pantomime and the country house charade are the most living drama today." The remainder of this 1935 statement continues as a plausible programme for a kind of theatre that we have come to know since, but which Auden could not then have seen in England, except in some very modest form, and which is not quite the same as what was being proposed by Brecht and others in Germany.

What happened to be missing for Auden was the ideal collaborator, the dramaturg or director who could shape and adapt his insights. He still wrote a volume's worth of plays, of which the best is The Dog Beneath the Skin, on which Isherwood was his co-author. But he did not produce what Eliot briefly produced in Sweeney Agonistes, an original, and completely successful, concept of poetic drama. He turned to opera and wrote, with Chester Kallman, two important libretti: The Rake's Progress for Stravinsky and The Bassarids for Hans Werner Henze. But the relationship with Benjamin Britten, from which one might have expected most, did not work out in the end. Whether it could have done so might well be doubted: not every writer can play Hofmannsthal to Richard Strauss, and not every composer would know what to do with a Da Ponte, should one suddenly knock on his door.

The editing of Auden, which has been such a success, has proceeded at its own grand pace: a volume of plays, a volume of libretti, a short volume of juvenilia (always fascinating) and two large volumes, so far, of prose. The guiding spirit in all this has been Edward Mendelson, Auden's literary executor who, along with scholars such as John Fuller, Nicholas Jenkins and Katherine Bucknell, have begun to make it possible for us to see and understand his life's work whole.

The large Collected Poems was first established three years after Auden's death (he died in 1973) along the lines the poet would have wanted - that is to say, respecting his revisions and omissions, which were once so controversial but which were, after all, within his rights. The English Auden, which came out in 1977, gave the reader access to most of the early work up to 1939. But one day there will be an even larger edition of all the poems, published, suppressed, rejected, revised, just as one day there will be what Auden did not want but is inevitable - a collected letters.

It is an immense amount of work, produced on a regime, whether it was drugs or alcohol, that eventually took its toll in the form of a great depression during the last year of his life, and an early - but much wished for - death. And it has been an immense amount of work for the scholars to lay the foundations for interpreting Auden's poetry. That he was a great public poet, despite his misgivings about the role, has always been acknowledged. But he was also a great lyrical poet, his achievement in love poetry being without equal in the century.

He worked through every poetic form he could find, rejecting only a few he found too trivial. He tried counting syllables. He tried counting the number of words in the line. He invented (as far as English was concerned) a discursive style that could accommodate the language of prose and the concern of science. He wrote many song lyrics. He always bounced off poetic influences, and he felt wretched when he couldn't find the next influence. In 1968, for instance, he was listening to the Beatles (he liked "She's Leaving Home", or was it "Eleanor Rigby"?) in search of something to be influenced by.

He appears to have felt (he says something to this effect), on completing a poem, that he would never be able to write another. And that must have been a nightmare to him, since he was always moving on to the next task, suffering failure sometimes, and aware of a widespread rejection of his later work, knowing himself often attacked, and unwilling to speak up in his own defence. He had a private, even secret, generosity to match the public generosity, the copiousness of his achievement. An enviable gift, then, although not always an enviable life - unless we say that in some cases the gift is indeed the life, and that the suffering is all part of the gift.

· Faber is publishing Auden's Collected Poems: Centenary Edition edited by Edward Mendelson on March 8, and a new edition of WH Auden: A Commentary by John Fuller on April 5