As far as my friends, those who like to listen to music tend to be optimistic about everything and have strong self-confidence. When I was a freshman student, a friend of mine quit the college, because he wanted to be devoted to musician. And, those who often walk inside the college with earphones or headsets are prone to skip lectures. But, they seem to be happy and good at flirting with girls.
Though it's impossible to know how happy they are, they seem to be happier than me at that time.