I've said this before, so forgive me.

There is an Irish (and probably a Scottish) Gaelic word 'sliebh' which is pronounced like 'sleeve' and means 'mountain.'

I'm sure this song was written by someone Irish or Scottish, perhaps a harper, and the original title had that Gaelic word in it.

It is no surprise to me that this beautiful melody from an oppressed culture was quickly trashed by being linked to prostitution. "That's what they do."