Why does everyone write music about love? If one were to take a survey of American popular music of the last 50 to 60 years and use that to determine what human life was like during that time, it would give the impression that love is really the only emotion that people feel, or at least the only one that people write songs about.
"Save the Last Dance for Me," "Unchained Melody," "Crazy Little Thing Called Love," "In My Life," "I Just Called to Say I Love You," "Wonderful Tonight," "I'll Be There," "My Girl" . . . the list goes on.
Think of the stupid songs we slow-danced to in middle school, believing that this one-hit-wonder gem perfectly related how we felt while we stared wistfully into our loved one's face from a safe distance. Clearly, there are other emotions we feel which have the potential to be - and have been - expressed through music such as anger, happiness, fear, awe, etc., yet the love song is the favorite by a long shot. Why is that the case?
There's the cynical take, which states that love is an effective mood which musicians use to sell music. If music is meant to be emotionally appealing, then love is an ideal topic. Everyone relates, or wants to relate, to a love story. It is universally ideal in a way that something like anger can never be in that it seems everyone is in some varying progression of a romantic relationship, or everyone wants to be there:
In a relationship? You relate to the song perfectly. Not in a relationship? You wistfully want to relate. Just done with a break-up? You sob into your gallon of Kemps Cookies 'n' Cream. Everybody is into it, so everybody buys it. Hence, capitalism, supply and demand, bada bing bada boom. All of a sudden, everyone is selling love songs. The less cynical side of the argument is to consider the emotion of love itself. Have you ever tried to describe the feeling of being in love? It is an exercise in frustration, the words rolling out like explorers trudging in molasses that has been frozen in a snowstorm. We end up talking about it indirectly. We write songs and poems and hope to God that someone understands us. Once again, a lot of other feelings come out pretty easily; hate, for instance, is easily described as the feeling you get when you would enjoy nothing more than kicking that ONE GUY'S TEETH IN GRAAAAGTHGH. Love does not come out easily, and so lends itself to strange side roads and metaphors that, to be completely honest, seem to have little to do with love itself.
Maybe the answer comes somewhere in the middle of cynical and hopeful. We write and listen to love songs because it is an ideal we want to experience. Why? Because we feel alone. While we surround ourselves with other people, filling up our headspace with incessant chatter, what we really want is something deeper with another person that extends past talk and moves into something more emotionally grounded. We presume that this "something more" is the feeling of love.
So we write about it, talk about it, try to feel it and listen to it. It is a shared experience of connection. Hence, a fitting topic for music, the most ready and egalitarian medium of human experience.