Reading McGrath's last contribution lead me to look back at the Act to see how incidental music is defined. I had previously assumed that it was, for example, music incidental to a play, and therefore implicitly covered by the licence for the play and mentioned explicitly in the Act to avoid uncertainty.

I find that I was totally wrong - although music that is an integral part of a licenced play is presumably licenced by the play's licence.

No. Incidental music is defined as "The provision of entertainment consisting of the performance of live music or the playing of recorded music is not to be regarded as the provision of regulated entertainment for the purposes of this Act to the extent that it is incidental to some other activity which is not itself

(a) a description of entertainment falling within paragraph 2, or

(b) the provision of entertainment facilities."

In other words any music that is not explicitly listed as requiring a licence is automatically permitted.

Paragraph 2 is the old familiar list including the important condition: "where the entertainment takes place in the presence of an audience and is provided for the purpose, or for purposes which include the purpose, of entertaining that audience."

In simple terms it excludes from licencing any background music, such as muzak in shops, which is not intended to be listened to by an audience in preference to other individual activities by that audience.

Although it might be rash to rely on such an assumption; my experience is that most sessions are essentially mutual navel-gazing without a fundamental intention to entertain anyone but the participating group, so it could be argued that a session is incidental even if it is obtrusive.