Rum, very rum. The German Constitution guarantees freedom of speech, whether spoken or sung. Musicians, vocal or instrumental, are also protected by the Article about freedom of art and science. In contrast UK seems to me more than medieval.
I think it crazy that people are forbidden to sing and play their own traditional heritage when gathering wherever it might be.
By the way, what about the funeral of a band or choir member? Will they be forbidden the good bye piece at the grave, too?

Wilfried