A vase of flowers blossoms behind us in the lounge bar of Mayfair's Cumberland Hotel as Amit Chaudhuri – novelist, academic, essayist and musician – engages in a detailed discussion of daffodils.

His erudite conversation is peppered with literary allusions. "Philip Larkin said that deprivation for him is what daffodils were to Wordsworth. For me, Calcutta is those daffodils, that source of inspiration," he explains.

The city blooms powerfully throughout all his work in a multiplicity of forms: in novels such as A Strange And Sublime Address, A New World and The Immortals; in his music videos, and now in his excellent new book Calcutta, in which he anatomises two years there while also peeling away layers of the city's past.

"Reality is for me something that is foreign and strange. It is unlike rather than like, and this is true of Calcutta. The Calcutta I loved had that foreignness and strangeness for me. It was that intrinsic foreignness of where I was that excited me," says Chaudhuri, an eloquent, seamless talker. He says he was aware from a young age, as he began to write his first novel, that it was reality rather than fantasy that interested him. "I wrote in a notebook when I was 24 years old that imagination and fantasy cannot be as unexpected and varied as reality. By then I knew I wanted to write about the commonplace."

The strangeness in the everyday and the extraordinary in the ordinary is wonderfully drawn out in his new book. One of its concerns is the nature of modernity. "Although I was growing up in Bombay, Calcutta is the first place I encountered the thrill of the modern and became addicted to it," he explains. "There are many ways of defining the modern but one is to say that an urban space, a man-made space, has some of the energy, wildness, unpredictability and randomness that we usually associate with nature. When Larkin, as connoisseur of suburban life in Hull, talks about the 'cut-price crowd', that is what excites him. That is what I encountered as a category of experience as a child in Calcutta; it excited me. Calcutta is a modern city. With Calcutta, there is a multiplicity of things happening and a multiplicity of historical remains."

Those "historical remains" are brilliantly interwoven into a "real-time" narrative as Chaudhuri captures the pulse of the here and now while also excavating it to reveal the forces that have shaped the city. Throughout the book is an evocation of beauty in urban space. "There is beauty for modernists as different as James Joyce and TS Eliot in the dereliction of the industrial city. It's important to record this history of response to Calcutta; because Calcutta is this so-called third world city, it will not be thought of by outsiders in this way. That it's both derelict and alive, those things energise each other. This is not to take away from the trauma that the city has come through."

The epigraph of Elizabeth Bishop's poem Questions Of Travel captures the book's subtle and perceptive exploration of the contradictory impulse to travel and yet remain at home. Having returned to Calcutta as an outsider paradoxically enabled Chaudhuri to get beneath the skin of the city. Born there in 1962, into "a small nuclear family", Chaudhuri grew up in Bombay and was educated in London and Oxford, returning only to visit Calcutta for short periods. "My mother was a great singer of Tagore songs but her interpretation of Tagore songs was completely unique and lacking in bogus reverence. So that made me aware of inheritance as a living thing and not as a dead thing to be revered. Physically being on the outside as I grew up in Bombay also allowed me to look at Calcutta and my own Bengaliness from the outside in all its complexity."

His engaging book draws out the particularities of cities while reaching a universality by being a homage to cities the world over. "It made me seek out the city in other cities I encountered and understand what it was that most excited me about cities, which wasn't to do with big buildings and shopping malls. What was exciting about cities was the ability to move through neighbourhoods and feel as if one were travelling from country to country – that sense of foreignness in unexpected places within the city itself."

Though Chaudhuri is Professor of Contemporary Literature at the University of East Anglia, married to Rosinka, a literary academic, with whom he has a daughter, he has always hoped to one day return to the city of his birth. "It was an unarticulated but real boyhood fantasy to move to Calcutta. I was miserable in school and miserable in Bombay for a number of reasons. I think it's a very exciting city now but it made me miserable when I was growing up. Calcutta is an amazing city and I wanted to be there." He also explains the poignant homesickness that pervades his work. "I wanted to go back to India because I would feel homesick, physically homesick in the sense of needing a certain kind of rhythm to the day, light, noise, in the absence of which I would feel a sense of withdrawal."

His masterful prose style lingers on the tiny, quotidian details and draws out their significance. "When I was 24 the discovery I made was that it was the pull of the elsewhere and the everyday that gave me great joy." Alongside novels he began to write critical essays, and has also edited the landmark volume The Picador Book Of Modern Indian Literature. As a child he wanted to be a poet and rock musician. "I had a multiplicity of ambitions but writing was always there."

The book has a unique and fascinating form. It was his agent who initially suggested writing it, predicting a boom in non-fiction writing in India. It was an idea to which Chaudhuri was initially resistant but eventually he came to see how it might work. "I was not going to write a kind of conventional non-fiction book. I was instead going to allow one thing to unexpectedly lead to the other. And I would be there in it. It's a great pleasure to write in that way. In my fiction, I've always explored the edges of what is conventionally called fiction." His work does indeed explore the boundaries of form in an invigorating way. As he explains, "I am uneasy with accepting certain stable categories which form the basis of the way we think about genre."

Calcutta draws on rigorous research including interviews with a wide spectrum of society, from the homeless to politicians, and captures the political upheavals in the city as well as the waves of migration that have shaped Calcutta over the past 30 years.

"In those two years I was witness to political change – which actually changed nothing – but was also coming to terms with what the city is now. I would go out into a street I knew well and talk to people I didn't know well.

"I felt that I was now able to map the city and be part of it in a way that I hadn't before. There were these shared journeys. Being there and talking in these shared spaces made me connected to the city."

He approaches the political situation "with exasperation", explaining that "one begins to wish for a space which is apolitical. In Calcutta one urgently needs a space to be creative because everything seems to be politicized, not in an idealistic way but with petty power politics. That has strangulated Calcutta."

Chaudhuri remembers novelist Pico Iyer saying to him: "Aren't you one of the most rooted people? You write so intimately about home." Yet as Chaudhuri has written: "I write intimately about foreign places and foreignness, home enmeshed with elsewhere. It's that enmeshing that really interests me."

Returning from Britain to his parents' house in a Christian area in Bombay, with Portugese architectural influences, he became attuned to the foreignness within cities. "I've realised that this is what I've written about; a kind of break in the norm; a visit in the midst of the city itself when you're suddenly elsewhere. All my books seem to be structured around visits; not plot but visits and what this does in terms of transforming you and the way you look at your surroundings."

Calcutta certainly transforms the way one looks at things, and as I walk back out into the swirl of Mayfair, I begin to notice details that had previously slipped me by, the hidden beauty in the everyday urban chaos now everywhere apparent.

Calcutta: Two Years In The City by Amit Chaudhuri is published by Union Books, £16.99