Do we listen to music when we are in love and we are happy? No, we usually don’t. We then listen to the music of our hearts that beat in tune to the one beloved.
We listen to songs about love when it is bad times for our love or when we are lovesick.
Pragmatically the musicians know that songs about suffering love are the most money-making. The reason is that people want somebody to be present near them in times they are in love grief, for somebody to articulate their suffering. It is called empathy in psychology. This is the process when somebody shares the same feelings as you do. Musicians are psychologists. They cure our souls with their music.
On the other hand: too much of sad depressive music catalyzes of your sufferings. Some bands even “advise” their addressees to jump off the roof. Think one has to perceive that very figuratively. Such suicidal motifs can be mostly found in the repertoire of “Muse”.
The lexicon of the songs about love is also so crammed with the words like “broken”, “hurt”, “heart”, “only you”. “Radiohead” uses also the word “bruise” as the alternative. And the pronoun “you” is the most widely used.
The saddest thing is that everybody who listens to a song about love imagines oneself at the place of the singing one and always wants to address the one he/she loves but is unable of that.
Still, songs about love prove that this feeling is not only the chain of chemical reactions.