If music is all about connecting us to a group, why do people listen in solitude as well?
I think even when you listen by yourself, what makes that feel good is that you are kind of being tricked—much like when you watch TV—into thinking you're interacting with people, tricked into thinking you're part of a group. Our core motivation is to feel like we belong. Anything that tricks you into feeling that way is going to feel rewarding, you're going to pursue that like a drug.
("Why Did Humans Invent Music
?", Marc Silver, National Geographic, Published August 24, 2013)