‘Oh yes?’ The violinist turned his bright, girl-preoccupied eyes towards him.

Ulli prepared to unleash Willy Strecker’s idea. ‘Now,’ he began, ‘what would you say if I were to tell you that there is a violin concerto by Schumann that is never played?’

‘Schumann?’ said Yehudi, his face alight as if a magic strawberry ice cream had materialised before him. ‘And… is there?’

‘There is.’

‘Really? Where? Why? What’s it like? Why isn’t it played? Can I see it?’

‘It’s in the Prussian State Library in Berlin. We have been attempting to acquire the rights to publish it, but the family is very resistant and at first they made it impossible.’

‘And now they’ve relented?’

‘Not exactly, but we’re working on it,’ said Ulli. ‘There’s a new director at the library’s music collection – his name is Dr Georg Schünemann, and he used to be director of the Berlin Hochschüle für Musik, which is where I studied. We’re hoping he will be a little less intractable than the gentleman who has, er, gone.’

There was, unfortunately, reason to believe that Schünemann had already been tractable – as Ulli had discovered that very morning.

With several free hours in Paris before joining Menuhin’s recording session, Ulli had taken the Métro to the Rome stop, intending to spend some time visiting music shops near the conservatoire to meet and charm the proprietors, as Willy had requested. Music transcends politics, he said to them; they hastened to agree. He wondered if they really believed it. He scarcely did so himself; it was, as always, a useful excuse for deflecting more important issues. One store was displaying the latest issue of the magazine La Revue musicale. He picked up a copy and leafed through it. Then he stopped, blinked, stared.

He had not imagined it. He was gazing at an article about the Schumann Violin Concerto, written by a German musicologist named Hermann Springer. There, on the bright new paper of the December 1935 edition, was a facsimile of the first page of the piece’s slow movement, in manuscript. Ulli hurried into a spot where the light was better. The bulb cast its glow onto the staves of Schumann’s handwriting. He saw a suggestion of syncopation, some offbeat counterpoint, a simple melody written in an odd, complex way. For several minutes, focused on the very thing he’d been trying in vain to unearth, Ulli lost all sense of time and place.

Once the shock wore off, he forced the cogs of his brain into action, trying to visualise how this could have happened. Clearly, the Nazis were letting their own people in on the secret concerto. Perhaps there was more to that official ‘embargo’ than he had been led to believe.