This guy, in his army green sweater, somewhat full of himself, playing his guitar for, I assume, the pigeons.
He was on the bench just inside the gate on the Charing Cross road side. I did several of him, as he was settled there for a while. And you get to wondering about back story. All the guitar shops are just around the corner, has he just brought it, and is breaking it in ? Or one last tune before he sells it ? Or maybe he has just had it restrung ( my lack of knowledge of guitars painful there, think I am confusing them with tennis racquets ) Or is that pure conjecture, based on my always ferocious desire for narrative ?
The Background Extras in your story are the Undaunted Heroes of theirs.