Either there is some bug with the music not looping or it's implemented terribly in this game. Seems that location specific music plays and loops correctly (villages, cities etc.) but whenever not in these specific areas, it's either completely quiet or the track plays exactly once. Reloading a save makes the music play, but it barely ever persists for a longer time and very soon disappears completely again.

Any potential fixes?

EDIT:
The music seems to stop during the night. During daytime, it usually plays correctly.