But this autumn has been different. Firecrackers have ripped through the night but there have been no splashy film openings. A handful of new films have begun their runs with minimum fuss. The studios are eerily quiet. In the audio studios, mixing and dubbing of films already in the can proceeds, but no new scores are being recorded. The stars are photographed, not out promoting their new work, but shuttling between home and the city's police stations or hemmed in by bodyguards. Bollywood is scared. A string of murders and attempted murders this year and the attempted extradition from Britain of a famous music director called Nadeem, to be tried for alleged involvement in one such killing, have underlined how Indian film-making is entangled with organised crime.
As a result, the industry has gone into a funk. It is reflected in the films they make: the success of a film about the Indo-Pakistani wars has been followed by a string of high-profile flops.
The biggest event in Bollywood's crisis occurred in August, with the shooting dead of a film-industry tycoon called Gulshan Kumar. A pudgy figure who had started out selling fruit juice on the streets of Delhi and clawed his way to the top by making and selling bootleg audio cassettes, Kumar was an important man in Bollywood. Practically all India's commercial films are musicals, and Kumar owned the audio rights to many of them. He had a near-monopoly on the all-important music dubbing in the industry and had just signed up several directors to shoot films for him.
He had also become religious, and on 12 August was returning from prayers at a temple of Shiva, which he had rebuilt in marble in the midst of a Bombay slum, when a long-haired youth in blue jeans held a gun against his head and said, according to witnesses: "You've prayed enough. Now you can pray up there." Minutes later he was dead, with 16 bullet wounds.
It was a corny, garishly "filmi" death, as they say here, but, following earlier assaults on other film-industry figures, it sent a shiver through Bombay. In March, a producer called Mukesh Duggal was shot dead outside his office. When two other producers, Subhash Ghai and Rajiv Rai, narrowly escaped being murdered soon after the announcement of the success of their new films, people started to pay attention. The word was that the gangs were demanding huge slices of the profits of new pictures - typically, the rights to overseas distribution - and, when rebuffed, were making their dissatisfaction plain in their own way.
Gulshan Kumar's murder underlined the fact that the industry had become frighteningly vulnerable: as many as 150 celebrities, it was said, had received threats, and many of the most famous were subsequently given armed bodyguards. In September, Bombay police announced that a star music director called Nadeem was to be extradited from the UK to face trial for his involvement in Kumar's murder; the extradition hearing is set for 24 November.
Bollywood's chronic problem is that, because of the risks involved in financing films and the government's refusal to grant it the status of a proper industry, it has always had difficulty raising funds to make its films. The finance is raised by individual producers, not studios.
By Western standards, Indian films used to cost peanuts - in the Sixties and Seventies pounds 120,000 was enough for a standard picture - for, with few alternatives, the mass of Indians gladly flocked to their fleapits for entertainment. But with the arrival of satellite and cable television five years ago, Bollywood got its first taste of serious competition. Its response was to go for the blockbusters - wide-screen musicals shot in exotic locations. The blockbusters cost more than pounds 1m; and, flush with funds from narcotics, prostitution and property deals in booming Bombay, the gangs were happy to oblige. Soon between 20 and 40 per cent of Bombay's movies were being made with the help of underworld money. For, like gangsters everywhere, Bombay's hoods are in love with showbiz; the biggest name in its underworld, Dawood Ibrahim, adorned hisparties with stars and foisted his favourite actresses on reluctant producers. It had the makings of a cosy affair. But as the columnist Parwez Hafeez points out: "One could invite the mafia in, one could not order it out."
With the collapse of Bombay property prices over the past two years, and the dwindling of their other sources of income, with the exception of narcotics, the gangsters have been hard-up for ready money. So when one of their old friends in movies strikes it rich, what could be more natural than to renew the acquaintance? Hence the sudden, uncharacteristic premium on failure in Bollywood today.
"Everyone knows my last film was a big flop," star producer Subhash Ghai, whose murder was flukily foiled earlier this year, insisted recently. "I lost a lot of money. I don't even have an imported car. How can anyone call me a showman?"
Producers are praying that their new films fail. In an industry as mercurial and frothy as this one, such a mood cannot last. The risk for Bombay is that by the time confidence returns, the vast captive audience will have persuaded itself that it is just as much fun to stay home and watch the box.