There is a discussion going on in another thread concerning the notorious 1954 definition of folk music--a close reading of that definition suggests that the hymnal which Mr. WAV is "top-lining" doesn't qualify as folk music at all, because "The term does not cover composed popular music that has been taken over ready-made by a community and remains unchanged" The music in the hymnal being written, arranged, and intended for performance in a standardized fashion--

So whatever sentiments the melodies may evoke, they are composed music, and not, in and of themselves, folk music. When Mr. WAV plays the "top line", he is simply playing a composed piece of music. End of story.