The sound of a tango by Argentina's best-known composer, Astor Piazzola, electrified the street with its dissonant rhythms and nervous energy. The awaiting crowd transformed themselves into dancers and within minutes, almost the entire street was in motion. It was then I realised that attending the annual tango festival in Buenos Aires called for active participation.
Young danced with old, strangers with strangers, foreigners with Argentines, amateurs with professionals and the casual with the elegant. A laughing English couple were practising their first steps under the amused guidance of a pair of Argentines.
One elderly lady dressed in black, wearing a string of pearls and perched on impossibly high heels, stood on the sidelines. The music changed to a piece she obviously loved, and she began to sway on the spot. Opening her eyes wide, she looked around for someone who would dance her off her feet. A young man wearing a duffel bag, jeans and a Mettallica T-shirt inclined his head politely as their eyes met. Gently - and expertly - he swept her away, leaving his duffel bag in the charge of two old ladies who laughed gleefully.
Elsewhere, a group of five teenage girls sat in a circle at the side of the street. Later, I saw one of them dance delicately past with a fragile-looking old man. I asked one of them why the tango had become so popular again with young people, as during the 1980s and early 1990s it was perceived as something only old people did. "Because of the crisis," she said with an ironic laugh. "During such times everything is put into question and that, I believe, tends to make people search for their roots."
This is at least one of the reasons why this old Argentine lament for hard times has witnessed a revival in recent years. Tango is a new social language, temporarily dissolving the boundaries between people. Its origins lie in the tenements and bordellos of late 19th-century Buenos Aires, where it became popular as an expression of the displacement, loss and disillusionment felt by a new wave of European immigrants who were disconnected from their past and uncertain of their future.
Its melancholy melodies and sensuous rhythms gradually won acceptance among the higher layers of Argentine society. Tango's appeal peaked in the 1920s and 1930s, thanks largely to the charismatic singer Carlos Gardel, who remains a potent icon in Argentina nearly 70 years after his death in a plane crash in June, 1935. It has since fluctuated in popularity, being suppressed as a subversive force during Argentina's various military dictatorships, and also giving way to other popular music trends.
But tango clubs and street dancers are now commonplace again in Buenos Aires, even outside the festival season. The tango - in its various forms, from the old-guard milongas to the experimental, "electronic" variety - has become a means of connecting with others as the Argentine people struggle to come to terms with the huge political and economic uncertainty the last few years have brought.
Since the economic crash of 2001, when the peso lost 75 per cent of its value overnight, Argentina has been struggling to pick itself up. The past three years have seen a rise in crime, unemployment, inflation and emigration. Since the banks' freezing of assets in 2001, many people refuse to trust them and keep all their money hidden in their homes. Anyone who owns anything is fearful of losing it. Government taxes are seen as another way of robbing citizens and there is a general reluctance to pay them.
While Europeans can enjoy the country's immense tourist resources at extremely low prices (the euro is currently worth 3.80 pesos), the average Argentine is grounded and for many travelling even within their own country is too expensive. In the poorest northern provinces, children are dying of malnutrition. The government subsidy for unemployment is just 200 pesos (€52) a month, far from enough to feed a hungry family.
Yet in spite of such levels of poverty, Argentina is showing some signs of recovery. The strengthening of domestic industries and the consumption of Argentine-made products is replacing the high demand for imports from Europe and the US which dominated the 1990s. Last year saw an increase in exports (up 18 per cent from 2003) and a decrease in unemployment to 12 per cent.
The devaluation of the peso has also rendered Argentina an affordable destination for many foreigners, especially Europeans, Americans and Japanese and the numbers of Europeans visiting the country has risen dramatically in the past few years.
Much of this tourism is directed towards cultural activities, such as attending tango shows and classes, or visiting the popularly termed "taxi dancing" clubs, where foreign amateurs pay to dance with local experts.
Argentines now look towards this investment from foreigners both as a significant source of income as well as a much needed affirmation of themselves and their country.