As explained in the TG4 program, the Irish language song Abha an tSuláin is a geographic description of the course of the river, written in response to another local song which got it wrong!The English language song, The Banks of Sullane, is a love song based around the same area. I don't offhand know its age and provenance - though it has a whiff of the 19C. "hedge school" tradition about it.

Both are fine songs - but there is no connection between them other than the name of the river.

Regards