You can listen to most of the music used here: https://www.youtube.com/watch?v=xxXzrEs1q3c&list=PL6wFp1CClQzxD49KOEzu5IevZpn3Rf...
When a new OST is written it will be uploaded somewhere, in the meantime you can puruse all the audio/music files in the game files at any time!