Opera: Everything she did was definitive

It's 20 years since she died - but Maria Callas lives on in the memory and, now, a play. Michael White considers a legend

Opera has always been a necrophiliac affair, ruled from the grave by the small but perfectly formed fioritura of long-dead divas and steeped in a despairing certainty that we shall never know their like again. The pessimism tends to be unwarranted. But in one case it speaks true: Maria Meneghini Callas. Her fioritura wasn't so perfect (or so small), but, 20 years after her death, she reigns irreplaceably in the hearts and minds of millions; and now lives again on stage, in Terrence McNally's Tony- award-winning play Master Class, transferring from Broadway to the West End.

Whatever it means to be a legend, Callas was it; and not only for what she could do with her voice. The details of her adversarial relationships with opera-house intendants, fellow artists and her family ("I wouldn't give her the lice from my hair" she said of her destitute mother) were bus-stop conversation in the 1960s - rivalled only by the scandal of her extra-marital association with Aristotle Onassis, and the minutiae of their life together on the yacht Christina where guests reputedly bathed in champagne or, more conventionally, drank it on bar-stools upholstered in whales' foreskins. How many foreskins it took to upholster a bar-stool was all part of the mystique.

As for the voice, it was a matter of fierce controversy and remains so - although you would need to be of a certain age and in the right place at the right time to have experienced it live. London was special to Callas - she had a close relationship with Covent Garden - but she still gave only 38 staged performances here in what was by any reckoning a short career. It peaked and finished early, leaving her at the top of her profession for 10 or 12 years at the most: from the late 1940s to the early 1960s. The last years of her life were spent in chic but lonely semi-retirement. And she died at 53.

It follows that when most people talk about Callas, they're talking about the experience of her on disc; and that, at least, is plentiful. It was a miracle of timing that she came to prominence at the moment when technology produced the modern LP. EMI moved in on her at speed, in 1952, with an exclusive signing that was probably the most enduringly profitable deal the company has ever made beyond the Beatles. It resulted in one of the great catalogues of recording history: 24 complete operas plus 11 recital discs which have been sold and resold in every viable format ever since. They access the reality of Callas's achievement in a way that cuts through legend, gossip, genitalian bar stools and whatever else distracts us from her singing.

But because Callas was supremely a dramatic artist who lived for the stage, her recordings - most of which were made in studio circumstances - can tell only half the story. And it is a complex story, hard to disentangle from the embellishments and half-truths that attach to it. Even her date of birth has never been exactly established, but it was some time in December 1923. Her parents were Greek immigrants to New York, and when their marriage collapsed she was taken back to Athens, where she studied and built a local, teenage career singing Toscas and Fidelios for German troops in wartime Occupation. After the war she got her first big break at the arena in Verona where she was taken up by the conductor Tullio Serafin and found a dedicated, rich if ageing husband in Giovanni Meneghini. Then came reinvention: she transformed herself from dumpy plainness into the sophisticated, ever- posing icon of a thousand Cecil Beaton shoots. Her glamour advertised and virtually defined the qualities of diva-dom. Her passion, on and off the stage, was textbook. But in 1958 it overran. Within the year she walked out of a gala performance for the President of Italy, turned her back on La Scala, Milan (the central pillar of her singing life), and got fired from the New York Met. On the rebound from all that, she met Onassis and eventually threw aside her marriage, work and credibility in favour of a public and prolonged whale of a time on the Christina. The director Zeffirelli coaxed her back to Covent Garden for his classic 1964/65 Tosca (classically still running: it was on only last month), and it provided her last appearance in a full, staged opera. All that remained was a series of masterclasses in 1971-72 at the Juilliard School, New York - the subject of McNally's play, which stars Patti LuPone as the declining diva - and a sad recital tour with the tenor Giuseppe di Stefano. By then, her lover, her confidence and her voice had all deserted her.

Why did the voice give out so soon? Probably for the same reason that it was such a remarkable instrument in the first place. It did far too much. Voices are fragile, and in the effort to preserve them singers tend to concentrate their work around what Germans call a "fach": a division of repertoire. During the first half of this century the sense of category was rigid and demanded a choice between either coloratura roles (the decorative, high-flying nightingales of Bellini, Donizetti, early Verdi) or dramatic roles (the heavier, heart-on-sleeve creations of late Verdi, Wagner and Puccini).

Callas did them all. By nature she was a dramatic soprano, heavy with what I've heard described as the voice of Greek Islands washerwomen on a Monday morning, and equipped for vocal bulk in Turandot, Aida and the Wagner heroines which were among the first things she tackled. But by training she was also able to sing coloratura. And so it was that nightingale roles began to appear in her schedule as well - against the rules but with important consequences for the art of singing in that she carried through to this traditionally decorative music an empowering depth of feeling nobody had found in it before. It was a striking marriage between flexibility and strength; and the supreme, showpiece vehicle for it was Bellini's Norma - her greatest role, which she recorded twice and sang on stage 84 times.

To hear those recordings - one from 1954, the other from 1960 - is to understand what made her special. The athletic energy, the fire, the glamour is unique: no one before or since could charge this music with such raw exhilaration. But raw is the word. Callas never offered the conventional, seamless beauty of coloratura sopranos like Joan Sutherland or Marilyn Horne: her personality was too volatile, her approach to singing too self-sacrificial in its love affair with risk. Callas was a great artist for the same reason that she was a difficult woman. She demanded everything and more; and if she was tough with others, she was tougher with herself.

To that extent, she lived her life like one of her own heroines, fulfilling the standard expection of women in opera: that they sing, suffer and die. Callas's last, reclusive, lonely years in Paris and Wagnerian death - she seems to have just faded away in a resigned delirium - could almost have been scripted. And if she was playing a part it was, like everything else she did, definitive.

It's tempting to exaggerate Callas's part in music history. Although her repertoire rode roughshod over fach divisions, it was not so big: essentially Italian tragic roles, nothing (on stage) in French, not much in German, very little comedy. And it was, of course, entirely opera. There were no song recitals. But she certainly breathed new life into the whole genre of bel canto singing: finding it a new, excited audience, and re-establishing forgotten works. She had extraordinary ambition for the music that she championed. And for a short while she was probably the most dynamic singing actress in the world.

In both the good and bad sense of the word, Callas was a diva, and perhaps the last of her kind. The succeeding generations of female stars - te Kanawa, von Otter, Bartoli - tend not to present themselves in quite those terms. Only a few still try. And they discover that the culture has moved on.

! 'Master Class' is now previewing, and opens on 6 May, at the Queen's Theatre, W1 (0171 494 5040).