Takes two to tango

"Tango without nostalgia is not tango. It is a form of language without words but that language is one of heartache.

"Many of the immigrants knew they would never see their family or friends in Italy again, that is what tango expresses. It is not a wave hello to a new country but a long wave goodbye."

The costumes - men in double-breasted suits, women in high heels - were the "clothes of immigrants", but they also served a practical purpose. "It is about freedom of movement," Mr Alio said. "The man leads so the woman has to turn, hence the heels - it is to keep them literally on their toes so they move their feet quickly."

As he was speaking, Mr Alio and his wife, Maria del Carmen, put two students from Houston, Texas, through their paces, demanding each painstaking step be executed with distinction and verve.

Yet across from the studio, tourists are being lured into tango coffee shops where dancers pose for photographs and "perform" a tango. Two dancers both in their twenties charge tourists for watching and for a fee will gladly pose for photos.

"I am not against 'tourism tango' as such but the trouble is people will think this is the genuine article," Mr Alio said.

"What you see in coffee shops like this is just for show and a quick profit. There is no feeling in the dance. It is entertaining to a point but it is not what tango is about. That is why its heritage must be recognised and the reason for the dance understood."