He ought to be playing "Nearer My God to Thee," like they did on the Titanic. Just before it sank.
I think it’s a stretch, or perhaps an oversimplification is more correct, to say it’s mostly about sex. I think it’s far more about the mysteries of love, of which sex (in the song) is a relatively small part.
Incidentally the music was written by Lowell Mason, who also wrote the music for "Joy to the World," which we will be hearing frequently in the coming weeks.