Sankha Guha describes the fast-changing landscape of the city of his birth

Money is flooding into the vascular system of India like a hallucinogenic drug. And the blood rush of new wealth is conjuring a new self-image – one that is shouted up in every commercial break of the myriad new TV networks. New India drives a 4x4 on long, empty, un-potholed roads; it works in spotless steel-and-glass IT enclaves and it plays in a profusion of sub-continental Buddha bars. It is, of course, still a collective mirage, but the belief is palpable, the hunger almost hurts – the dream of New India is to be ... the West.

I am back in Delhi, the city of my birth. I am here to reset my compass, to work out how much of my childhood is still on the map. It starts promisingly at Indira Gandhi International Airport, which is every bit as tatty as I remember it. Like much of Delhi, it was built by Bob the Builder's dodgy cousin, Jerry. International arrivals are greeted by exposed pipes, loose wires snaking out of holes and a huge brown slick congealing on the wall next to the baggage carousel. So far, so reassuring. Outside the terminal I get the first shock of the new. The car park is bristling with large 4x4 estate wagons, their shiny chrome bull bars announcing a new menace on the already anarchic roads. I feel a twinge of nostalgia for the bone-shaking Hindustan Ambassador – based on the 1948 Morris Oxford – that was built under licence and for decades was almost the only model to be seen on Indian roads. The old slugger is still in the ring but no longer the reigning champ; the day is coming soon when the Ambassador will look as much of an antique here as the Oxford is in the UK.

The driving, though, shows no sign of changing. The Indian highway code must be a very pithy work, containing one simple injunction – if you're bigger than the others, use your brawn, and barge. The rear ends of trucks and buses still carry hand-scrawled notices requesting drivers to "Horn Please". Amid the resulting cacophony, vehicles overtake on the inside, on the outside, in straight lines, in diagonal shimmies, and through the eye of a needle. Passengers of a nervous disposition absolutely need not apply.

The Imperial Hotel on Janpath (one of the arterial boulevards of New Delhi) was very much part of my old Delhi. The hotel of my memory was an institution – as a child I was vaguely aware that it had played host to the likes of Nehru, Gandhi, Jinnah and Mountbatten as they decided the fate of the sub-continent – but in more recent years it was a shabby, atmospheric and peeling shell. A huge investment has returned the Art Deco hotel to its "former glory" – I hesitate to use the phrase because it is hard to imagine the hotel was ever quite as buffed as it is now.

From the moment you sweep past the 24 towering king palms in the drive and are decanted into the scented cool of the lobby by an army of eager flunkies, the clamour, the heat and the dust of Delhi fall away and you become aware you have entered an exalted realm of almost indecent luxury.

Nowhere does deference like India. I hazard a guess, but the staff-to-guest ratio at the Imperial must be something like 25 to 1. At reception there is an elegant sari-clad lady whose job description is best summed up as "lobby hoverer". Should a guest look remotely at a loose end, she hovers over and purrs something along the lines of "I hope sir is having a good afternoon". There are greeters and smilers, door openers and luggage wallahs, bellhops and concierges, and bowers and scrapers coming out of the cracks – except there are no cracks.

The room rates match the service. But the restaurants are open to non-residents, and a lime soda sipped slowly on the Imperial's turquoise pillared veranda will not break the bank while providing a delicious, if guilty, pang of Raj nostalgia. It is here that I become aware of a bizarre new New Delhi phenomenon – discreetly placed speakers emitting a lumbering beat, a whumping sub-bass, topped by pointless Groove Armada-lite doodles. The chill-out muzak is not remotely Indian but it, and a thousand faceless tunes like it, have become the soundtrack of ambition in Delhi.

Chill-out follows me around like a migraine. It is the first thing I am aware of when I step into Veda, a newish restaurant housed in a former billiard hall in Connaught Place. The second thing I become aware of in the dimly lit interior is, in the words of King Tut archaeologist Howard Carter, "gold – everywhere the glint of gold". When my eyes have adjusted to the gloom I discover an interior bedecked in red chandeliers, Venetian-style glass mirrors, rococo-style armchairs and gold-painted ventilation ducts. The food is no-nonsense Mughlai fare and pretty good, but the musical accompaniment I learn is from a CD called The Music from Fashion Week: New York, London, Paris.

There is more of the same later, at Tabula Rasa, a lounge bar/restaurant favoured by the young entrepreneurial set. On the roof terrace of a shopping mall in south Delhi I find myself buried in a beanbag sipping imported Hefeweizen beer. The marketing executive of the "trendy new restaurant" explains why its music policy is entirely Western. They never play Bollywood hits, she says, because that wouldn't give the right message: "We want this place to be classy."

The night takes on a more surreal turn as I move on to Agni, a nightclub back in the centre. A 35ft bar runs along one wall of the dance floor and the bar staff are doing brisk business at 2am. Delhi's rich kids are here in numbers. The DJ is spinning hip-hop and R&B. A teenage girl with a tattoo on her shoulder is showing off grinding moves cribbed off the Pussycat Dolls on MTV.

A big shout of recognition goes up in response to the opening bars of a song by hip-hopster Akon, which has the euphemistic fit-for-radio title "I Wanna Love You". The non-airplay version is predictably raunchier. And all the young Delhi hos are eager and ready when the chorus comes around, gleefully mouthing "I wanna f**k you, (f**k you) you already know, I wanna f**k you, (f**k you) you already know". None of which would invite comment in the fleshpots of London or Manhattan, but this is still India – where public displays of physical intimacy are still regarded as indecent. And where only last year Bollywood A-listers set off a national outcry and even faced a criminal prosecution for daring to depict a kiss on screen.

But vast swaths of life in the capital still follow patterns I can recognise. The beggars are still here. They still ambush cars caught at traffic lights. A businesswoman I meet spins me a local variant of the trickle-down theory of wealth. "For the beggars it is booming," she says. But the limbless and the ragged I see bedding down on the pavements don't seem to have heard the good news.

At the heart of Lutyens's imperial Delhi, around the monumental India Gate, I join the local version of the passeggiata as twilight descends. The autumnal air is balmy and this is the best part of the day. Families have brought picnics; lovers are flirting over spicy snacks from street stalls, and little urchins are weaving through the crowd selling candy floss, oversized soft toys, balloons and glow sticks. The smell of barbecued sweetcorn, bhutta, rises from small braziers in the gutter. An old man is sitting cross-legged on the pavement with bathroom scales, offering his weighing service for one rupee (less than 1.5p) per person – in the darkness he reads the results with a torch. This is the Delhi of my childhood, and one that seems obstinately at ease with itself.

Driving back to the hotel in the dark I am struck by an absence. The horse-drawn tangas and bullock carts have disappeared. The streets no longer carry the sharp whiff of dung and urine. On Shah Jehan Marg I notice a new steel bus shelter just like the ones in Europe. The ad on the bus stop depicts three elegantly attired, fair-skinned women (like the ones in Europe) and carries the strap line: "Before it's in fashion, it's in Vogue".

Delhi is in transit. Mother India is stumbling on to the up escalator. It is an occident waiting to happen.

How to get there

Cox & Kings (020-7873 5000; organises tailor-made packages to Delhi and throughout India. Its Indian Experience tour includes two nights at the Intercontinental in Delhi, with a tour of both Old and New Delhi, and costs from £995 per person, based on two sharing, including return flights with Jet Airways, transfers, b&b and all excursions. The seven-night itinerary also takes in Agra and the Taj Mahal, Jaipur and an overnight stay at a royal mansion near Bharatpur.

Further reading 'The Last Mughal: The Fall of a Dynasty, Delhi 1857' by William Dalrymple, Bloomsbury, price £8.99