How about another angle?

When we record a CD ourselves, we have to pay the MCPS who administer royalties in respect of the copyrights on the music, lyrics and arrangements.

We then place MPCS on the insert to certify that this has been done.
For small-scale recordings, they take our word on how many have been produced, and charge us accordingly at a scale rate.

The pressing companies for proper CDs make returns (to MCPS?) on how many copies they have pressed, so you can't avoid them knowing. It is possible to avoid this by burning CDR's and just not telling them, but this is defrauding the copyright holders.

Copyrights like this obviously CANNOT be avoided by bankrupcy, as the composer of a tune may have no contract with the recording company. Whoever issues the recording is liable for the royalties.

(Logically, therefore, I suppose that copyright on songs and tunes written by the performers, and also their arrangements, should remain with the artists, not with the recording company - is that right? Remembering that Nic Jones wrote some of his tunes,, and arranged almost all of them. Legal advice required here)

Therefore, if one finds CDR (or CD) on sale with (just one) copyright SONG or TUNE and no MCPS logo, there is a legal problem, which MCPS would probably want to investigate. And copyright is claimed on a surprising number of 'traditional' songs and tunes. (Wild Mountain Thyme, for one well known example).

If the CDR DOES have an MPCS logo, then the MCPS would presumably know how many were declared. And the royalties are paid at this point, NOT when the disk is retailed.

We know there are CDR's out there, does anyone have details of any such recordings which may contain copyright songs or tunes?