"Public = the public can in effect get in."

But what is "entertainment" in this context? The Dudley guidelines appear to indicate that payment was a necessary condition.

There re all kinds of things which people can get into which are not counted as "entertainments", even where they might be quite enjoyable. Political meetings, church services, funerals, auctions...

But Shambles - as I read it, it isn't that two musicians playing together in a pub do not per se counted as public entertainment - it's that if this is counted as public entertainment, there is an automatic permission for it, under the pub's license.

But it is quite arguable that in certain circumstances musicians playing in a pub are not providing a public entyertainment at all (however good they may be). Their playing is merely incidental to the real business in hand and therefore specifically excluded from the definition of public entertainment.

The point being that the customers should be presumed to have come there primarily for a drink and to meet friends, and have not paid any admission charge. Musicians in this context are no more an public entertainent than the pictures hanging on the wall are an art exhibition.