Critics complained about the sound, despite the glass acoustic panels

But some fans were unhappy with the new theatre, which is located in an old industrial area in the outskirts of Milan.

Inva Mula, the Albanian soprano, sang the main role of Violetta Valery. She was substituting for the Chilean singer Christina Gallardo-Domas, who was sick.

The role of Alfredo Germont was sung by the Argentine tenor, Marcelo Alvarez, who had performed it before at New York's Metropolitan Opera and in Tokyo.

Opening up opera

There were mixed reactions from members of Italy's elite and opera fans, who had their first glimpse of the ultra-modern soaring glass and concrete structure of the Arcimboldi.

One fan of the new venue was fashion designer Giorgio Armani, who said the new theatre, with its extra 500 seats and in its new location, had opened up Milan's traditionally exclusive opera set.

La Scala will reopen in three years

"It is very open, very full of people, a different type of people," he told the Reuters news agency, adding his approval for the simple, hardwood-finished interior which is a contrast to the ornate, 18th century Scala.

The Italian sculptor, Gio Pomodoro, said: "This is the theatre of the future, beautiful and without frills."

But one businessman, Renzo Radaelli, expressed the view of those who were less impressed: "La Scala is something else. When you walk in you feel the history, you know that where you sit, Verdi, Bellini and Donizetti used to sit too," he said.

"This theatre," he said, "it's just like any other theatre, really."

Opera experts criticised the quality of the sound, despite the moveable, glass acoustic panels that flank the auditorium's walls.

"The sound is quite harmonious but the orchestra was too present compared with the voices," said Carlo Maria Cella, an opera critic for the newspaper Il Giorno.

"The sound at La Scala might be drier, a bit harsher, but it has a big presence. Here, you don't get that sense of presence," he said.

Debut performances

Marco Tronchetti Provera, the chairman of Pirelli, and his new wife, a Tunisian-born model, were among the celebrities who attended the inaugural night.

Mr Pirelli paid for more than half the 44m euros ($38.90m) it cost to build the Arcimboldi and it was the couple's first public engagement since their wedding in December.

The new theatre is located in a former industrial area

The opera company began its season at the old venue, with Verdi's Otello starring Placido Domingo on 7 December. Its last performance there on was on 30 December.

La Scala's renovation is expected cost $49m - more than the construction of the Arcimboldi.

The old theatre's stage is to be repaired and the storage area improved by December 2004.

Officials say that after La Scala reopens, the Arcimboldi will house theatre, touring opera and special Scala performances.