There was a time when the jubaan of a large part of North Southasia used to be called Hindustani, and films of Lahore and Bombay both used it un-self-consciously as their lingua franca. Then came the terrible partition, and Hindustani lost out. To the extent that you could not even say 'Hindustani classical music', with some people veering towards 'Southasian classical' as a way out.
Hindustani's decline was dictated by the hegemonic rise of Hindi and Urdu in India and Pakistan. While there was genuflection towards Urdu in the beginning (including the opening credits of Bombay flicks in Arabic script), the politics of demography and language has made Hindi the true hegemon of the Subcontinent as a whole. In the last decade, it is Hindi's Bambaiya patois which has become ascendant ("Apan ko roz roz ka lafada nahi mangta hai!").
Now television has slipped into the role prepared for it by latter-day Bollywood and Hindi is the unquestioned transnational mass-market vernacular, having crushed Maithili, Braj Bhasa, Bhojpuri, Rajasthani, Magadhi, Awadhi, Bundeli and others along the way. In the larger region, the power of Indian multinational satellite television makes Hindi the medium of entertainment right across the east-west expanse of the Subcontinent.
Hindustani has lost this war of the vernacular. As the name of a language, it supposedly does not exist any more, with the Indian state and society preferring Hindi and Paksitan favouring Urdu. For the parochial Indian establishment, 'Hindustani' refers to the tongue of the Muslims (almost as much as Urdu), whereas for the chauvinists of the Pakistani establishment, 'Hindustani' is marred by the reference to 'Hindu' which is retroactively inconvenient.
It is all very confusing. It turns out that Hindi and Urdu are one and the same tongue that differs only in the upper reaches infiltrated by Persian and Sanskrit. As the scholar Afroj Taz (born District Etah, Uttar Pradesh, now teaching Southasian languages in North Carolina) says: "Hindi and Urdu, which share a common, identical grammatical structure must be considered a single language: Hindi-Urdu."
The fact that Urdu is in fact Hindi and vice-versa would be a matter of some discomfort to a few on either side of the LoC, but the very fact that Bollywood films are consumed voraciously in Pakistan proves the point. No one would claim that Pakistanis watch Bollywood blockbusters because they know Hindi. Ergo, they are listening to Hindi-Urdu as one and the same language. Which means that even though the Bombay producer and director thought they were making a film in Hindi, they are heard in Lahore as Urdu. When this Nepal-based writer goes to Lahore, he is ridiculed for his bad Urdu, and in Delhi for his atrocious Hindi. Or Hindustani.
In heavyweight gatherings of Southasian states, diplomats from Kathmandu, Dhaka, New Delhi and Islamabad alike are found succumbing to what is/has become the common jubaan of North Southasia, quoting Iqbal, Faiz and Shair Ludhianvi. Away from diplomatic decorum, they ascend to a language that is neither Hindu nor Urdu but an evolved medium of conversation carrying the heritage of the Indus Valley, Awadh, the Padma, Tipu Sultan and Dilip Kumar. Hindustani.
Naming of the shared language as 'Hindi-Urdu' does not really work. Nor would it help to call the tongue 'Hindurdu' or 'Urdhindi'. Another time, another day, when the geo-political hackles are down permanently, perhaps we can indeed go back to 'Hindustani', which would be most satisfying. It is an evolved name, it packs in just the right amount of multi-layered-ness of Southasian society. With 'Hindustani' there would be no need to invent a new word.
It is just possible that the need for a name for the joint language will be felt among the people once the India-Pakistan thaw accelerates, and the economic, social and cultural links between Northern India and Pakistan take firm root. When that happens, lets pronounce it and spell it as the original 'Hindostani'.