like the usage of the word bodhran, it received wide currency in the 50's but the concept was known before then. Though the actual description of the word may have eluded folklorists in the Victorian era.
Hootenannies date from the 40's, ceilidh (in its literal translation) is much older than that. And I don't doubt the C# would have met in a suitable establishment, alcoholical or not, before they built C# house. And songs would have been sung for the enjoyment as well as for the erudition. And like SAR these days, discussion would be part of that.

What strikes me quite often is that people's idea of what is very old has a cutoff date around the youth of their parents or grandparents (depeding on their exposure to memories from those antecedents). Earlier than that is considered very very old (especially if it is Folk) ie maybe 100+ years. Speaking from personal experience - revelations about a song's (ie) provenance can be surprising after having "assumed".