Talent and commitment are two important ingredients for a musician, but few are gifted with another quality that is just as vital for survival today — a head for business.

Unlike rock and pop concerts, live classical music cannot be kept afloat by ticket sales. Concert-goers are sometimes surprised to learn that even when the tickets cost £50, they are heavily subsidised. This is despite the fact that musicians earn little money and lead a precarious existence as freelance operators.

Nevertheless, the Orchestra of St John’s has flourished since it lost its Arts Council funding more than a decade ago. Its director, John Lubbock, said: “A few years ago, the Arts Council had this idea that there were too many orchestras in London, where we were then based. Luckily, I have a few private individuals who have been loyal supporters.”

The orchestra can only survive thanks to three Oxfordshire businessmen — Toby Blackwell, of the bookselling family; Rick Rowse, of the Wallingford honey-makers; and investment banker Martin Smith, who has also endowed the Smith School for Enterprise and the Environment at Oxford University.

Mr Lubbock founded the orchestra in 1967 at the age of 21, having just graduated from the Royal School of Music in London, and says nothing had prepared him for the job.

“I studied singing, and had not even done any conducting. I spent two weeks with a Romanian conductor in Germany, which was wonderful.”

He continued to work as a singer as he built up the orchestra, performing with the Swingle Singers, who rose to fame in the 1970s, until the orchestra broke into the big time with a US tour and then a permanent residency at St John’s Church in Smith Square, London.

His wife Christine Cairns is also a singer, and until the 1990s they shared the lifestyle of globally recognised musicians as the orchestra filled concert halls in Vienna, Berlin and Amsterdam.

His world changed in 1992 with the birth of his son Alexander, who is autistic. “Up to then, we toured the world with the orchestra, but from the moment he was diagnosed we decided to do this rather intense therapy with him. We realised that if we were going to do this, there would be no travelling.”

The orchestra already prided itself on its community links, and is now based in Oxfordshire, while continuing to fill larger venues such as the Queen Elizabeth Hall in London.

“I haven't been abroad since Alexander was diagnosed,” said Mr Lubbock. “That is why I started doing concerts in Dorchester Abbey, which is near where we live. We have kept the same musicians, because for them it doesn't matter if it is London or Dorchester.”

He closed the London office to save money, taking over the administration of the £350,000 turnover enterprise himself.

“I realised that the percentage turnover that was going to the management was ridiculous, so I got rid of the office and now I run the whole thing myself. It has been very interesting. I was already raising all the money, and now the whole thing is much quicker because they used to ring me three times a day. It is a unique pattern, forced on me by Alexander, but I enjoy it,” he said.

Now the money raised can be used for its prime purpose — paying musicians. Except for the BBC Symphony Orchestra, there are no salaried musicians in England, so they are paid on a freelance basis.

The Orchestra of St John’s has 100 players on the books and needs 20-40 each time, using a core of loyal players. “Only ten per cent differ from concert to concert. Some of them have played with me for 35 years,” said Mr Lubbock.

Raising money for mainstream concerts is not easy, but he also has funding for the other major string to his bow — a charity called Music For Autism, providing concerts for people with autism and their families.

He believes music has a profound effect on individuals who may not respond to other things. “The response is so spontaneous. We go to a lot of special schools and you can see their feet start going, or their hands.”

He added: “The players love it. It reminds us of why we went into this business. I am very lucky — I would do this for nothing. In the big orchestras there is tremendous pressure and some conductors are difficult to work with. I think this is a more fulfilling life.”

He is constantly on the lookout for new revenue, and has recently formed a partnership with Blackwell's, which promotes the concerts in its music shop, and with the Ashmolean Museum, which runs concerts linked to exhibits. October's prom, for example, features Purcell's Dido and Aeneas with a talk on the painting Aeneas’s Farewell to Dido by landscape artist Claude Lorrain.

Another innovation is the Conductor’s Circle, a membership scheme offering discounts to regular concert-goers.

Other forthcoming events include a performance in the Queen Elizabeth Hall by Derek Paravicini, a virtuoso pianist with autism. The Dorchester Abbey festival runs from September 16-18.