People of exaggerated and intractably opposed viewpoints eye each other with mutual suspicion and contempt while shrieking incessantly. And all around, onlookers stare transfixed as events begin sweeping to their inevitable and tragic conclusion.
Not for the first time in Italy, life is imitating art as its opera houses head for the kind of fate that befalls the doomed protagonists in works such as Verdi's Il Trovatore.
In the real-life melodrama, Silvio Berlusconi's centre-right government is being portrayed as the executioner as it prepares to pass a law that will reform the country's archaic, failing and cash-strapped opera houses, by not only introducing more discipline but also cutting back even further on the amount musicians and performers earn. Critics say it is a recipe for disaster.
The emergency decree announced this month by culture minister Sandro Bondi has sparked a wave of unrest across the country, with headline opera performances axed without mercy by furious unions.
A long-awaited performance by Placido Domingo in Verdi's Simon Boccanegra – in which the great man was due to make a rare appearance as a baritone – failed to escape the chop, as musicians protested at what they see as government plans to cut costs and their wages.
No one doubts that with the worst of the wildcat strikes over, it will soon be business as usual for Milan's La Scala, which, as possibly the most famous opera house in the world, benefits from earning a greater proportion of its income privately than other Italian opera houses. Milan's upper classes, who arrive in chauffeur-driven Mercedes and populate the historic theatre as ordinary people would a social club, needn't fear for the establishment's future.
But across Italy, the birthplace of the art form, the future of many other opera houses looks ominous indeed. First-night performances of The Barber of Seville at the Teatro Regio in Turin and of Madama Butterfly at the Teatro Verdi in Trieste were cancelled this month, for instance, a Don Quixote performance at the Teatro Dell'Opera in Rome also bit the dust, while the Accademia di Santa Cecilia in the capital halted all concerts.
The government decree that kicked off this month's wave of unrest stands to become law within 45 days. And if that happens, say observers, it could well be curtains for opera production in many of the country's other 13 establishments, with crippling industrial action and plummeting balance sheets.
An emergency degree, which has never been issued before for arts funding, was prompted by the government's desire to reduce the £225m state subsidy and force opera houses to banish what it sees as arcane work practices. Ministers want theatres to make the most of the funds they have and are aware that around 70 per cent of the state funding is currently swallowed by wage costs.
Somewhat perversely it sees the abysmal state of the opera houses' finances as its justification, with theatres in Rome, Naples, Florence and Genova, more or less bankrupt. Bologna could be next. "The situation is catastrophic," said Alberto Mattioli, a leading critic on the Italian daily newspaper La Stampa.
"It really is disastrous," he said, "with the government failing to give the money opera needs, and the situation being made worse by the ridiculous and indefensible position of the unions, which gives ministers an excuse."
Like other observers he says it's hard to see why actors in Verona get paid extra if they wield fake swords, or why performers in some theatres can demand more for singing German.
The crisis facing opera houses should also be seen in the context of an already grim financial landscape. In 2009 only 936,000 people visited the opera in Italy. And this was a 5 per cent drop, or 60,000 fewer, than the year before.
This has led many to question whether Italian opera houses, particularly the smaller ones, have a future. The Scala's chief spokesman Carlo Maria Cella said: "The decree is very bad for La Scala, because it reduces our flexibility – our ability to pay musicians and workers what we need to.
"But for the other opera houses, the cut in wages and the cut in state funding that it implies will prove, I think, extremely damaging. I do wonder how many of the 13 other opera houses or symphonic organisations will survive."
During a rare break from preparations for his midsummer five-opera spectacular in Verona, Italian maestro Franco Zeffirelli told The Independent there would always be demand for quality productions, but some of the productions didn't deserve to succeed.
"There is a lot of very bad opera and that's why so many opera houses are empty," he said, adding, "not in my performances" which "regularly get 90-95 per cent full houses".
The legendary director, who is currently working in Verona for the city's Opera Festival, designing and directing productions of five famous works – Turandot, Aida, Madama Butterfly, Carmen and Il Trovatore – is not noted for his reticence.
"You can't keep making opera that doesn't have the support of the public," he said. "Quality has to be top priority. And what you can't have is a situation where the state is effectively propping up bad productions. There's no point in this at all."
Mr Mattioli of La Stampa also attacked as what he sees as the myth of the quality of Italian opera. "The fact is repeated like a mantra which everyone takes as the truth, but which really isn't: that the opera houses are an excellent Italian thing." Aside from La Scala, "the international importance of our theatres, even those with a prestigious history, is negligible," he says.
But along with other opera experts, such as Valerio Cappelli of Corriere della Sera, he says it is clearly the government's responsibility to fund Italian opera to the degree that it is able to flourish.
"Italy is the home of opera," said Mr Cappelli. "The Government should give something of this cultural importance more money. Unfortunately this government, as we have seen, is not a friend of culture. Opera is something it sees as privileged and decadent."
Most observers think the ministers in the current administration are not happy that opera eats up 47 per cent of the entire state budget for the arts, which also covers cinema, the theatre and concerts.
Critics joke bitterly that the writing was on the wall for Italian opera when the populist premier Berlusconi snubbed a key VIP society fixture in December, the glittering opening night of Carmen at La Scala, for a night at the cinema to see the special-effects-laden blockbuster 2012 at the local multiplex.
Mr Zeffirelli is scathing about the government's attempts to tell theatres how to operate, despite his position as Senator for the ruling centre-right Pdl party. "[Mr] Bondi should not be involved. People who understand and appreciate the opera should be discussing its future. He doesn't know anything about the performing arts."
"The government is very, very wrong," added Mr Mattioli. "It doesn't seem to care or understand that opera is a vital piece of our heritage in the way that Shakespeare is for the British. But at the moment the situation is beginning to look like a tragedy."