It may be that in musical retrospect, from a luxury of twenty-twenty critical hindsight, that Astor Piazzolla will be seen as having done in the twentieth century for the tango what Frederick Chopin did in the nineteenth for the waltz. It is perhaps already an accepted position. With the waltz, Chopin took an established popular form and stretched its boundaries so that what an audience might have expected to be a little ditty was recast to express heroism, sensuality, pride, or even occasional doubt. The little dance tune then, in Chopin's slender hands, became an elegant art form, highly expressive, utterly Romantic in its ability to convey human emotion.

The tango represents an apparently different proposition. Already sensuous by definition, there are elements of the romantic towards which the tango need not aspire. If Romanticism placed individual emotional responses upon the pedestal of artistic expression, by the time the tango aspired to truly international currency in the twentieth century, there was no longer any need to worry about an artist's right to make a personal statement.

With the rise of serialism, neo-classicism and, later, minimalism, artistic mores were already, perhaps, heading in the opposite direction, towards a new espousal of rigour and structure. Emotion worn on the cuffs, like concepts plucked from the back of a matchbox, seemed to dominate cultural activities in the latter part of the century whilst, at the same time, Althusser and Derrida, allied with the populism of mass culture, seemed to suggest that there were no new statements, let alone discoveries, to be made.

A spectral free-for-all ruled, where distinctions of quality were suddenly both particularistic and individual to the point of exclusion. (This, of course, is necessarily a paradox for people promoting a populist pop culture, since they aspire to mass consumption of a single artistic vision, a statement that by definition cannot be worth more than any other - even randomly selected statement. As a result, those who tend to deny a critic's right to make value judgments must themselves assume that such judgments are perfectly valid in the marketplace.

It's a contradictory position, but an essential one for purveyors of pop, since they must continue to describe the form as popular, despite the fact that the vast majority of its products prove themselves to be anything but.) Post-modernists thus hailed the soap opera alongside Shakespeare, a logic that renders a Coca Cola advertisement the greatest film ever made by virtue of its viewer numbers. And then there was Piazzolla, an enigma par excellence.

On the one hand Astor Piazzolla is the quintessential mid-twentieth century composer. Classically trained, a pupil of Alberto Ginastera and Nadia Boulanger, and inspired by the commercial and folk music of his own country, he could have slotted alongside Villa Lobos, Ponce, or even Martinu or Copeland as a contributor to the century's neo-classical-folk music paradigm. But what he did was quite different.

He devoted his compositional energies to recreating and reinventing a popular idiom that was thoroughly specific to his own country, Argentina. The form, of course, was the tango. What is more, Astor Piazzolla concentrated on performance via his own ensembles and he achieved considerable success, albeit local until near the end of his life, over a career that spanned fifty years. But he expressed himself on the bandoneon, a squeezebox that lends itself to staccato, slapping attack, an instrument not peculiar to Argentina, but perhaps only well known to Argentinians. He died in 1992, his Romantic heroism national at best.