...But for that, perhaps we'd all be singing Leadbelly songs to this day...

If, and only if, Leadbelly was "Policy." Meanwhile, American folkie Harry Belafonte (RIP) once claimed most American Jews learned Hava Nagila from him.

There is minor argument here about what LLoyd did. The big deal is in the opinions on same. A "Policy" of exclusion is about the only way to manufacture the false consensus nobody needs.