I'm no authority on the Ottawa Valley - but I'm willing to run off my mouth till one comes along .... There were French-Canadians and, no doubt, Aboriginal people living in the general area from early on; there were two main waves of Irish immigration: one, late 18th/early 19th Century; two, Famine/Post-Famine (i.e., 1830s/40s). What the proportion of Orange to Green was, I have no idea. There would have been some Scottish immigration, but I don't know how much. And some English, presumably, but my impression is that the bulk of settlement was Irish.

Lumbering was the big economic activity, so many men spent much of the year in whatever sort of camps went with whatever aspect of lumbering they were involved in - and those camps were hotbeds of folklore/arts of all kinds. And there was considerable contact via the Ottawa and St. Lawrence Rivers with Ottawa and Montreal. So, room for all kinds of influences and creativity.

Having said all that - I don't know quite what those mostly-Irish settlers brought with them in the way of music and dance. Reg Hall in his book on Irish music in London talks about dance and music in Ireland at the period in question - but I've forgotten most of what he said ... !