“THE BETTER we know a work,” said Alfred Brendel, who has spent his life exploring masterpieces on the piano, “the more it surprises us.” To understand Brendel’s remark it was necessary only to be in Usher Hall in Edinburgh the other night to hear Sir Charles Mackerras conduct Beethoven’s Sixth Symphony with the Scottish Chamber Orchestra, a performance of such beauty and freshness that it emerged as truly shocking.

Mackerras is in his 81st year, yet he directed his players with the curiosity of a man who had just stumbled across the score, which in a sense he had. Every interpretation of a great work is an accumulation of every performance of that work ever given and also a first night.

At Edinburgh this year, as every year, visitors to the festival — the various festivals, one should say — are bombarded with images of young people. There are, apparently, scores of “daring” comedians “tackling” issues of the day, which is just another way of saying that their prejudices are more enlightened than ours. So thank goodness that, when it comes to being truly daring, one needs the ears and eyes of somebody who has lived a bit.

After all, what is more shocking — telling people what they want to hear, which is what the young have done down the ages, or thinking afresh about the most affecting music known to man? It was the measure of Mackerras’s achievement that the Pastoral, Beethoven’s most familiar symphony, sounded as if the composer’s monograph was still wet on the score.

Mackerras is not the only senior citizen to show younger men the way. Sir Colin Davis, 78, conducted a magnificent Elgar Two at the Proms this week. Nor is the wisdom of age restricted to musicians. Alan Bennett and Michael Frayn, who will not see 70 again, have written their best plays in the past two years. William Trevor, 78, remains the most beautiful writer in the English language.

In one of his American poems, Auden declared himself “unready to die but already at the stage when one starts to dislike the young”. One should never dislike the young. Their heads are full of dreams, and they will find out soon enough that life is more difficult. Those in Edinburgh should make a start by rushing along to the four remaining concerts in the Beethoven cycle to listen, and wonder.