Your re-invention of the term makes Bach a folk Composer, Maria Callas a folk singer, Jeffrey Archer a writer of folk stories and Rudolph Nureyev a folk dancer - and 'The Birdie Song a folk song

Maria Callas is/was am opera singer ~ Rudolph Nureyev was a ballet dancer Bach was a composer of orchestral music ~ they fall into a different class
~ Jeffrey Archer is a novelist!

Folk music is music of the people, basic compositions as is folk song, carrying on the tradition without actually being traditional!

Folk song is a living entity whether it is deemed traditional or Contemporary folk song

We are all people ~ I hope!

Ray