The music is touching, just wonderfull. But for that you must have played or seen the game, which is, when you accept what it is and try it for yourself, one of the best games in the last years if you want something that touches you.
The music is a great part of why the atmospere in "The Unfinished Swan" is just that good.
I could go on but sadly I am no expert in music, so can´t throw more fancy words at you or explain it better to you.
I also recommend for you (if you liked this and/or the game) "What Remains Of Edith Finch" which is from the same developers, also an amazing artistic game with a beautiful sad story.