The greatest British orchestral composer of the last fifty years was not someone of whom we have never heard, whose state subsidised music is played only by state subsidised musicians in state subsidised venues. He and his music are in fact very well known.

John Barry, who died last month, merits comparison with the great “classical” composers – and was able to combine artistic achievement with huge commercial success.

So why was this outstanding Briton, who was admired all over the world, never given a knighthood by his own country? After all, lots of the obscure state subsidised types were knighted. That is, of course, the point.

Like many of the most talented and successful Britons of his generation, Barry was a tax exile. He was forced to live abroad by British tax rates that were punitive in the most literal sense – they punished achievement.

As a result, instead of receiving a reasonable portion of his considerable earnings at the peak of his career, the British state got nothing from him. Withholding a knighthood was the state’s petty revenge for a situation created by its own short-sightedness.

Eventually, again like many of his contemporaries, he returned to Britain in the 1980s after Margaret Thatcher reduced higher rate tax. It is therefore no surprise that the total paid in taxes by higher rate taxpayers in Britain actually increased as a result of that tax cut.

So Boris Johnson, the Mayor of London, is right to call for similar tax cuts today. He is certainly speaking in the best interests of his own city. London has probably benefitted more than anywhere else from the relatively low tax rates that prevailed from Mrs Thatcher’s time until very recently. Not only did the capital become home to a disproportionate number of the returning exiles; it also attracted a large number of wealthy foreign entrepreneurs. These people have contributed to the local economy, and they have also enhanced London’s social and cultural life. It was after the tax cuts that London regained its Swinging Sixties reputation as one of the most exciting, vibrant, and “happening” places in the world.

Nor is it coincidence that many of the talented people who made the original Swinging London in the Sixties became, like Barry, tax exiles in the Seventies. Those who think them hypocrites for that should ask if the real hypocrites are not those who impose taxes on talent and then wonder where all the talented people have gone.