This must be more of an issue that side of the pond. Here licensing is strictly a local matter -- back in Chicago, when I lived there, you were in big trouble if you had public entertainment wo a license. Here, we routinely take over a pizza joint for a singaround.

On a side note, this whole thread reminded me of a library job long long ago and far far away (well, chicago, again actually) where a buncha plas three sheets windward took over the bicycle rack right outside the big window and bellowed out for what seemed like hours. They could not be dissuaded, at least until a library patron called the cops. When we, the staff, remonstrated, they simply demanded to know how good they sounded. (Not.)

(I'm also told I was singing in the recovery room lately, but I don't remember anyone telling mo to shut up. But then I don't remember singing, either.)