Clever stuff. I can't help wondering weather it was popular music that imprinted the scale in our modern minds. The good old Blues scale we hear over and over again. Interestingly the Sellingers Round tune was imprinted in our minds in the same way in the 16th and 17th centuries.
However after a chat with an archaeologist at Horniman's museum some fifty years ago, she played a reproduction of a harp (style instrument) from mediaeval times that was tuned to a pentatonic scale. Like most discussions concerning musical history we come to a chicken or egg conundrum sooner or later. Leeneia's post may pose an unanswerable question. Not the end of the world music has no race colour or boundaries and all mediums are given universal ownership. We are none the worse for that.