We all like music. The most tone-deaf of us enjoy music. You can sometimes hear them, in the shower or in their car, dissonantly barking out a tune. We might not like a particular style (like rap or rock) but we all seem to enjoy music.
You know, I think that it might be something built into people. We take what moves us emotionally, or even just what is important, and put it into song. Knowing the truth of the alphabet is important: we put it into song. Our country is pretty important: we put that it into song. I really love my wife, my kids and my dog and have dreams of a mini-van: I better make a song. And if we want to get really serious, we sing about ideals which we cherish: like freedom, hope, goodness or love. Ooh: good songs. We sing what we believe in. What we think is important. What we hope for.
Animals just don’t do this.