The reason why that 'two-in-a bar-rule' existed of course is because somebody had the idea a very long time ago that two musicians can make a racket but nothing like enough to disturb the neighbours, whereas three and four and five - you are starting to push it a bit.

Now what has made a mockery of all of that is a guy turning up with a karaoke machine with a massive amplifier. Suddenly the game is very different, generally that is the thinking behind licensing music.

Sigh!