I have no expertise to offer, but a couple of tentative possibilities come to mind. Firstly, there might be something among the writings of the late John Blacking, who was interested in music as "a species specific characteristic" of humanity. Also, there is Stephen Mithen's book, The Singing Neanderthals. This doesn't deal directly with the question you have raised, but Mithen is interested in understanding how humanity developed musical abilities, and it seems to me that you are pursuing a similar area. So it may be that his book could point you to some parallel research.

Finally, and this really is about as vague as it can get, but in the early 1970s, A L Lloyd broadcast a series of programmes on BBC radio, called Music of the People (or some such title). In an episode dealing with lullabies he said something like "there are certain scholars who claim that a nation's music is shaped by the melodies a child hears when it is put to sleep".

That does admittedly sound like the sort of journalese which Bert was prone to lapse into. But it is possible that he was referring to a piece of genuine research - perhaps by one of the Eastern European scholars whom Bert was fond of rubbing shoulders with.