The words of a song lay always in the same place and they can be ever revisited.
The music in which they are caught makes them sufficiently smooth for understanding, so that it is not required an effort for understanding them each time when they are heard.
We may suppose that the most perennial words are those which do not need a thorough understanding. The religion confirms this supposition and often depends on music.
Moreover, we prefer those people from whom we exclude the effort of understanding their words. Our lovers are not perceived as speakers and their words can be ignored as like as the lyrics of a song, the sexual relations playing the role of the music. Ironically, the sexuality is the only situation when two mouths are in the closest nearness, but they are not used for talking.