Please define Folk music.
To me it means music that folk will sing. (Please define folk).
In my office recently I have startd people humming, singing such variety of music as the Sugur plum fairy, The Red Flag, If you are happy and you know it clap your hands, Suger Suger, Freight Train, 16 Tons, We are the Monkeys and other songs and instremental music.
I was not the only one to start strands
We are folk - we sing.
To me that is the defination of folk music, be it "popular music" or anon music. As long as people sing it that is folk music.
If it is good enough to last into the historic memories of the population it is good folk music.
However much I may dislike the song - Girls Just want to have fun - I believe that in 50 years that will be considered as folk music.
As long as people have voices, and will sing, Folk music is alive and well, living in the collective brains of the population.