Shambles,

We are getting closer to a common view. However, I suggest taht you are paying too much attention to the word "volume" which is not used in the Act and is only quoted as an example in the Guidance. All the essential information about what requires entertainment licencing is in Schedule 1 of the Act, but it is so heavily cross referenced that it is not easy to unentangle. I have spent some time trying and the following is my attempt to produce a somewhat more straightforward of condensing the means of determining whether music at a venue that is not licenced for musical entertainment is permissible or not. Try the following:

Is the activity under consideration subject to entertainment licencing?
        If not it is permitted. (Note that music is only permitted in this simple way as a result of acompanying
                Morris Dancing or similar dancing. NOTE that we need to establish that Longsword, Rapper and
                traditional clog dancing are similar to Morris. NOTE also that the arguments used to justify the
                Morris exception apply equally strongly to mumming and wassailing, but unfortunatley no-one argued
                this in Parliament.)

Otherwise
Is the activity in a place where the public is not present and which is not in a room in a licenced (drinking) club
        with club members present?
        If so and no charge is made for the room and the event organiser does not make a personal profit, then it does
        not need licencing and so is automatically permitted. Note that if the organiser is one of the musicians,
        he/she is entitled to his/her normal fee for performing without being classified as organising for profit.

In all other cases (i.e. either it is in a licenced club or is in the presence of the public or is in private but with
        the organiser or the premises provider making a profit):
Is there another concurrent activity which is the principle reason that those not participating in the entertainment
activity itself are present in the room?
        If so is that principal activity subject to entertainment licencing?
                If the principal activity (such as drinkingn at a bar) is not subject to entertainment licencing and
                the entertainment under consideration is the provision of incidental (supporting) music then the
                music is exempted from licencing requirements unless it overpowers the principal activity to the
                extent that it becomes the principal activity itself.

        Otherwise Since the principal activity is subject to entertainment licencing, is it licenced?
                If so the entertainment under consideration is the provision of incidental (supporting) music then the
                music is exempted from licencing requirements unless it overpowers the principal activity to the
                extent that it becomes the principal activity itself.

If none of the above cases is applicable
        A licence covering the particular type of entertainment needs to be in operation for the premises.

In all cases where a licence is required the only organisations/individuals who could be committing an offence are the
premises owners, the premises supervisor and the organiser of the activity. Participation alone is not an offence!!