I invented this field a while back. I didn't realize that "word and music studies" was a thing. But song studies is better than word and music studies, because of that troublesome word and. Word and music studies first separates the words from the music, and then tries to put them back together again. No.
Song studies says that there exists an artistic form that already has both words and music together. It is grounded on the intuition that poetry arises out of music, and that vocal music is the origin of music itself. Hence song is the originary point of poetry and music. It is ethnopoetics 101.