I made a strategic error.
When I was in Paris, I used to conduct a little choir and we wanted to sing outside a metro station. I suggested we contact the town hall or the police and ask permission but was told if we asked we'd be refused so just carry on anyway. You spend a lot of your time in France being ignored by the authorities so it's good to return the compliment. I remember writing assiduously month after month to the Mayor of Villejuif asking for a community hall to show a film and I never got a reply.
Anyway, I wrote to the organisers of the show talking about the parable of the talents project and the busking part of it and they somehow got the impression in spite of my lucid exposition of my request to busk around the site that I was offering to come and entertain the crowds. I think if I'd just slipped in with my guitar and sign everything would have been fine.
Had a nice day at Builth, as usual. Came back with a free energy saving device for the telly, a badge saying "I heart wind power" and the autograph of the actor who plays Hywel Llewelyn in Pobol y Cwm dedicated to the family. I shall prop it up by the TV each time the show comes on.