Richard, You are correct - it is highly doubtful thay JayZ would perform a Snoop Dog piece. Again, I consider that very similar to the "party piece" analogy and the fact that many collectors would find songs only in the songbag of a single family.

The sharing of songs and the "folk process" are parts of a larger process.

If you wish to cling to the 1954 definition, you can still have folk music without having a folk song.