The Sachal Studios Orchestra plays Take Five guardian.co.uk/Sachal Studios

The rich strains of eastern music have for centuries wafted across the rooftops of old Lahore. Now you might hear something new: jazzy riffs and a bossa nova beat.

An ensemble of veteran Pakistani musicians has pulled off an unlikely coup – storming western charts with an innovative jazz album and prompting comparisons with Buena Vista Social Club's rediscovery of a lost generation of Cuban musicians.

The Sachal Studios Orchestra has captured imaginations with a cover of Dave Brubeck's Take Five blending sweeping classical violins with sitars, tablas and other eastern instruments.

The piece has brought praise from jazz greats – Brubeck, 90, says it is "the most interesting" version of Take Five he's ever heard – and propelled the orchestra's album towards the top of the iTunes jazz charts in the US and UK. The album, which includes versions of The Girl from Ipanema, Misty and Desafinado, reached the top 10 in both countries.

"I'm so excited," said Riaz Hussain, the 55-year-old violinist who arranged the music. "I don't have words to express how I feel."

Recording at premises on the edge of Lahore's walled city, the 60-strong orchestra mixes local legends with musicians recently enticed out of retirement, some from lives of poverty. Few knew much about jazz before.

The project is the brainchild of Izzat Majeed, a millionaire philanthropist based in London. Eight years ago Majeed built a state-of-the-art studio for the orchestra: engineers from Abbey Road Studios provided technical advice, while western session musicians were hired to play instruments unavailable in Pakistan.

Although it cost more than $2m (£1.2m), his motive is music, not money. "To be honest, I never really enjoyed business," said the 60-year-old, who made his money in oil, gas and finance (he was involved in the $500m-plus sale of a Pakistani bank in 2006). "But I truly love this." His creation draws on multiple influences, from Lahore to Rio to New Orleans. And the buzz is building. The song's video has attracted a flood of internet hits, an Oscar-nominated Hollywood producer wants to make a documentary, and concerts are planned for the UK and US this winter.

Majeed's wider goal is to rub fresh magic from an old lantern. Pakistan's classical music scene was decimated in the 1980s, he said, when the dictator General Zia-ul-Haq crushed the local film industry, known as Lollywood. Several hundred musicians, employed to record film scores, lost their jobs. As the son of a hobbyist film producer, Majeed felt the loss personally. "Demand just collapsed after Zia," he said. "That guy dug the grave of Pakistan."

The cull forced many musicians into less lyrical trades, where they remained in obscurity for decades. Majeed found his cello player running a tea stall; others were selling clothes or electrical parts. Mubarak Ali, a shy 48-year-old violinist, was selling vegetables from his bicycle, earning barely £2 a day.

Now Ali's life has been transformed. At his home – a cramped two-room dwelling he shares with his wife, daughter and ailing 103-year-old mother – he lovingly lifted his cloth-wrapped violin from a case on the shelf. Then he pointed to a new fridge, DVD player and wooden bed. "Sachal paid for this, this and that," he said. "God bless Sachal. And God bless Majeed sahib."

Although named after a Sufi poet, it hasn't always been harmonious at Sachal studios. In the beginning, rival musicians competed ferociously against one another, Majeed recalled. "They wouldn't let each other play," he said. And it remains little known, even inside Pakistan. Pursuing music rather than promotion, Majeed had done little to push the jazz album until a BBC interview propelled it into the charts 10 days ago. "We haven't been very good at marketing," he admitted.

The confidence boost is urgently needed. Although Brubeck, Duke Ellington and other jazz legends performed in Pakistan in the 1950s, the turbulence of the past decade has isolated local musicians. Foreign travel is difficult and at home extremist violence has made concerts rare. So is growing conservatism – some Sachal musicians said they dared not practise at home, fearing they could offend pious neighbours.

Now success has brought fresh hope. "This is the first drop of rain," said flautist Baqar Abbas. "It shows that Pakistan is not just a place of bomb and suicide attacks." Ijaz "Balu" Khan, the orchestra's tabla player, said his dream was "to play solo with the orchestra in the Royal Albert Hall".

Such high hopes, and the Buena Vista comparisons, may be difficult to live up to; Majeed worries his musicians will not even get visas to leave Pakistan. But a second album is already in the works. "I speak music, I hear music. And now I want to live music," said irrepressible flautist Abbas.