The word 'folklore' is indeed relatively 'modern', indeed, having a traceable origin only 168 years ago. But the concept of "Tradition", with proleptic recognition of the "folklore" concept, is surely subsumed in terms like...

Doesn't matter when, Michael - I'm using the term Modern in the sense of relating to the present or recent times as opposed to the remote past, and by extension a remote or, indeed, lesser culture. In this sense the folk concept was always modern, even when Henry Purcell was setting what we'd now call Scottish Folk Songs over 300 years ago or else using Idiomatic Folk material in his operas (Come Away Fellow Sailors in Dido, Your Hay It is Mowed in King Arthur). Folk is very much of it's time, looking at something it assumes is timeless, and the bumpkin practitioners thereof innocent of it true provenance and / or significance.

Interestingly, as you are no doubt aware being the erudite chap you are, the first instance of a melody being collected from a tradition was when the medieval aristocratic Troubadour Raimbaut de Vaqueiras (1165 -1207) filched the tune he used for his famous Kalenda Maia from two duelling folk-fiddlers he overheard jamming in a field one day. Plus ça change, plus c'est la même chose! More bloody parlour arrangements!