Music is an art that goes well beyond science. Proof can be found in the huge amount of studies that have been carried out throughout the world based on music-therapy and the important results achieved.
I don't know if One Direction will stand the test of time. I have a niece who goes crazy for them. But the only way to judge art is to wait and see if it becomes evergreen. This takes a bit of time. Adele is a very good musician and I'd like to sing with her. But, again, time will tell if her music will become evergreen.
To sing a song is like whispering to a child's ear. It is an art heavily relying on improvisation.
I have trouble with modern art. But in general, all art forms fascinate me - art is the way human beings express what we can't say in words.