Musician Somjit Dasgupta is custodian of a stringed heritage

The way to Somjit Dasgupta's apartment, along a side lane in Kolkata's Ultadanga area is mostly taken up by vegetable and fruit vendors. It gives no hint of the treasures inside this 1,000 sqft space that houses a huge personal collection of sarod, sitar, sursingar and veena, and their variations – many of them centuries old and played by legendary Hindustani classical musicians of the last 200 years.

They lie scattered all over the apartment. There's a sarod in the living room, still encased in its blue travelling case covered with aircraft stickers. This one, Dasgupta plays, and before that his guru, Radhika Mohan Moitra, played. "It's more than 300 years old," says Dasgupta. Sarods, sitars and sursingars, carefully in plastic, lie atop steel almirahs, inside the box bed, on the sofa headboard, and hang from hooks in the rooms. There's a 300-year-old dhrupadi rabab that's still playable, a 250-year-old sitar, a sarod about 160-170 years old and a few instruments devised by Maitra – the mohanveena, dilbahar and nabadeepa.

"The core of the collection, 62 of the 200, was Radhubabu's (as Moitra is affectionately known in music circles)," says Dasgupta. Moitra was as famous and highly regarded as Ustad Ali Akbar Khan, Vilayat Khan or Ravi Shankar in the '60s and '70s. Sadly, forgotten today, despite being one of the most recorded artistes ever by All India Radio, Doordarshan and National Archives. He was a scion of the family of zamindars from Rajshahi, now in Bangladesh, that had emerged as an important patron of classical musicians in the century or so before 1947.

"Everyone from Ustad Faiyaz Khan and Ameer Khan to Ustad Inayat Khan, Dhruv Tara Joshi, Mushtaq Khan and earlier, Ustad Chamman Khan from the Rampur Court performed there. Ustad Kasim Ali Khan, a musician in Wajid Ali Khan's durbar and a descendent of Tansen, too, performed at Rajshahi. This is a chapter of the glory days of Indian classical music in Bengal that few people know today," says Somjit.

Moitra, and now Dasgupta's, collection of musical instruments originated with this amazing congregation – several of the eminent musicians left behind their instruments as a token of gratitude. Some others were gifts – for instance, "the nawab of Dhaka gifted a 270-year-old sarod in appreciation of their patronage of culture," Dasgupta informs. After independence, Moitra left behind his zamindari in Bangladeshi and shifted to Calcutta, carrying his musical instruments with him.

"I have been their custodian for the past 34 years," says Dasgupta, who has expanded the core collection with unique instruments that his guru had told him about, tracing them with the help of musicians, kaarigars and rasikas who have long patronised classical musicians from Jaipur, Gwalior, Pune and Punjab.

"But Bengal has the richest stash of musical instruments. I've found unique pieces in unlikely places – Ustad Waliullah Khan's sitar in a dilapidated house and a sarangi with a baiji (courtesan) in the red light district in Kolkata.

But keeping the collection in good condition is a task. "You have to play them regularly, tune and send for maintenance once or twice a year. They are living things, not dead objects in a museum." And Dasgupta bears the expense from his earnings at overseas concerts.

In 2003, Sangeet Natak Akademi held an exhibition of Dasgupta's collection, with talks and performances by prominent musicians. "There was a proposal to set up a conservatory of musical instruments – to train kaarigars to make copies for children to come over and play," Dasgupta says.

Though bureaucracy has delayed this proposal, it might get a new lease of life next year, Moitra's centennial year, which Dasgupta will celebrate with an international travelling exhibition of the rabab-sarod tradition in India and Moitra's biography. This time around, he's approached a cultural organiser from the private sector who is more appreciative of his endeavours.

But what is the fate of the instruments after he's gone? Can his students play these rare sarods? "Some of them can play one or two. But as Radhubabu would say, 'Indian classical music has a 6,000-year-old tradition and has weathered many a crisis such as this.' This one too shall pass."