I remember there was a discussion here or somewhere else about where sebene came from. Apart from who says what, today I found some interesting addition to this topic, wondered if you noticed it already.
By accident Google showed up an LP for me in the search results today, one that I never heard of yet: the title is Kasongo! and it is a record from 1957 from East Congo. I was surprised to see on the back, that next to the songs the genres are also listed, and some songs were marked as: Sebene. I thought WOW I need to listen, firstly because rural recordings are not common from those days, secondly because it even has sebene music, and I was surprised it was already an acknowledged genre at that early age of Congolese music. And very interestingly, the songs sounded as I expected from a sebene or something similar: