By the time the moment arrived, the request had turned into a heartfelt plea. “Today,” the stadium announcer said seconds before the referee blew his whistle, “we really must be a city united.” And with those words, 75,970 men, women and children in Old Trafford held their breath.

Who, with hand on heart, could have predicted with confidence what happened next? In one sense it was nothing as 60 seconds elapsed without a murmur inside the ground. Outside someone let off what sounded like fireworks.

But for those in the ground it felt like quite something, if not a sea change then at least a rapprochement of sorts as Manchester City supporters joined their Manchester United counterparts in observing a minute’s silence to mark the 50th anniversary of the Munich air disaster.

Is the willingness of 3,000 City fans to stay silent worth shouting about? Well, yes, particularly when one considers the alternative scenario that many of them felt was inevitable. For 99 per cent of them, paying their respects was natural, not least because Frank Swift, the former City goalkeeper, was among eight journalists who perished in the crash.

For a tiny minority, the ones who have chanted about Munich since terrace culture changed in the 1970s, keeping quiet may have gone against the grain. Yet they did stay quiet, to the immense relief and gratitude of everyone in the ground - particularly Sir Alex Ferguson, who immediately walked towards them to show his appreciation.

The commemorations of the past week have been about more than honouring the 23 victims of the disaster. They have been about education – and not just about educating the young or the supporters of rival clubs. There is also a minority of United fans who have mocked the tragedy, making pathetic aeroplane gestures at visiting supporters to demonstrate that songs about Munich do not hurt them. On visits to Anfield, United fans have been known to ask “Where’s your famous Munich song?”, the sub-text being that it died, along with 96 Liverpool supporters, as a result of the Hillsborough disaster in April 1989.

We live in a cynical age, one in which it was hard to imagine that the anniversary would be honoured with such decency, respect and, yes, class by both Manchester clubs and by all concerned. It would have been easy, after they were assigned a derby match so close to the anniversary, to take the easy option and opt for a minute’s applause, rather than to leave themselves at the mercy of City supporters. But to the delight of everyone, their faith was vindicated and reciprocated. “We’re the pride of Manchester,” they chanted defiantly once the minute’s silence was over and, after what followed on the pitch, it is a title they will guard with pride over the months to come.