He leads them up and down their scales and arpeggios. William is impressed. The overall sound is pleasing, albeit a bit gritty. He does his old trick of differentiating the voices, and this makes him notice individual faces, dissolves his sense that they are one, messy whole. He notices the delicate bone structure of the tenor opposite, his wire-wool hair roughly brushed and parted. He sees the wide-open mouth of the man to his left, with a front tooth missing.

‘William, can you give the files out, please?’ Martin points to a lopsided table in the corner and the pile of A4 ring binders, with ‘Midnight Choir’ written on the spines. They slither and slide in his arms as he walks round the circle. The men take the folders in both hands, two feet flat on the ground, sit up straight.

‘Number three then, to finish the warm-up. William, you’re going to have to play piano. Do you mind? I don’t know what’s happened to Jenny.’

He hasn’t touched a piano since he left Cambridge. Walking across the hall, he wishes that Martin had warned him he might be called on to play, but then the door opens and a woman William guesses to be in her forties runs in.

‘Sorry, Martin, I had a puncture.’ She hurries over to the piano, taking off her coat as she goes. ‘Had to go back and get my husband’s and I can’t cycle very fast on his. Hello, gentlemen.’ The woman waves quickly to the group and a ‘Hello, Jenny’ comes back. They like her, William thinks.

‘Not to worry,’ Martin says, ‘we’re just going to finish the warm-up with “Danny Boy”. This is William, Jenny, an old friend who’s helping out for a bit.’

‘Hello, William.’ She smiles, laying her coat on the top of the piano and opening the lid.

Martin gives her a minute to find the music, then raises his hand and nods at her. She plays a few bars of the introduction, her back and head swaying. It’s striking how the men are holding their books. Straight-backed, heads up. Martin has been channelling Phillip.

It’s patchy of course, but there’s also a richness to it William didn’t expect. They’re really singing. And somewhere in there are one or two good voices.

On William’s left is a gangly, skinny man, impossible to age, but his long hair and wispy beard are mostly grey. He’s on edge, eyes flicking to William often, but never resting long enough for William to smile at him. He’s not on the right page and isn’t singing, but William is wary of helping him. He’s wary of all of them. But by the second verse, he can’t stand it any longer. He leans across, flicks forward two pages and points briefly at the words they are singing now.