At 4am on 24 April 2019, 25 brass players, two percussionists and a conductor piled into a coach in Hull for a 200-mile drive to London. It was a Wednesday morning and it had been touch and go whether all of them would be able to get time off from their day jobs to make the trip. Seven hours later, they stood on the quayside at Greenwich, as Princess Anne swung a bottle of champagne at the looming yellow hull of the UK’s newest and biggest.