TOm, with respect, you're missing my point. Why shouldn't singarounds and sessions be included? They should be in premises with a PRS licence (obviously if they're not it's better not to draw it to their attention). If I play a copyright tune or sing a copyright song at one of these, why shouldn't the composer receive their share of the licence fee?

The GACS is for PRS members - essentially it is for composers and arrangers to report performances of their own material. If I understand PRS's website correctly (and its very difficult to find information on there), they now only take returns from larger concert venues, and for smaller ones they rely on sampling. This means there's no facility for non-members to reporting performances of someone else's work.

If sessions do indeed get sampled, I wonder how representative they are? What is bog-standard at one session may be unknown at one just down the road.

I'd like to think the folk world would be receptive to PRS. What it needs is a tariff system which reflects the economics of small-scale events, and a distribution system which gives people confidence that their licence fee will actually go to the artists whose work they perform, which in turn means an accurate system of reporting what is actually performed. Perhaps this already exists - if so, the PRS is doing a very poor job of informing people.