I heard this song when I was in secondary school in mid 70s, the chorus was so soothing and impressing although I didn't understand what that meant at all.... Last year I become grand father, I heard from my daughter the new mother tried to make baby sleep by singing something like "shule, shule, shule......" She even used an apps from Ipad to play the voice... Daughter said these are similar to what baby heard when it was still in mother's body.   Anyway, this is a special song that I won't forget. Thanks to PPM for making it popular.