Ooh, I met them last year (*) when they were doing this ...
They have played on the rooftops of every Anglican cathedral in England
... and a very cheery and friendly trio they were too. This was noble of them in the circumstances since I regret to say that
at least one Anglican Cathedral Health and Safety Officer had just vetoed their plan to play on the roof. They had to make do by playing on a balcony inside. But very nice it was too and they got a warm reception from the Extreme Cello Trio enthusiasts gathered below.
[(*) Their website says it was two years ago, 2006 . Time's bluddy winged chariot getting faster and faster again for the final furlong ) ]