@Illysia
Thanks. The suggestion was for whenever the "manpower" is planning to update the music.

@zanzibar
As shown by the graph, there is a huge volume jump starting in column 15. The first time you hear the track, you'll want to turn up the volume because it plays really quiet, only for it to become too loud past the the two-something minute mark. Having a good audio system and/or headphones makes a difference too.
@Madoring
Music matters a lot. It can set the mood and add to the overall atmosphere. Any games lacking in audio department will get their overall scores lowered by reviewers, and a lot of players simply like music in games. Have you considered why you didn't have the music on for years? Maybe that's a hint right there. Updating music won't take away from "different implementations" because it would be taken care of by musicians, except a small code update for a looping secondary track.
In addition to my original suggestion:When talking about factions and moods, I was, of course, referring to public areas accessible by everyone. Traveling around a city or exploring the open areas outside the cities. The traveling music doesn't quite go with the darker characters, for example. That's why I also mentioned the epic tracks that can, indeed, have a specific mood and be specific to a location, regardless of one's faction. Playing those tracks in a loop in regular public areas is what doesn't quite work for an overall atmosphere for some factions/characters.
Places only accessible by a certain faction, such as Black Flame temple, would obviously benefit from customized tracks, both epic and ambient alike. Death Realm should be pretty dark in music. And, of course, any areas meant to be dangerous, suspenseful etc can sound accordingly.
There are also exceptions like taverns, for example. It's ok to have that typical fantasy tavern music, even if it's cheery because that usually implies that some tavern musicians are playing it in the background, and that's what you would hear if you walked into a typical tavern. Unless, it's in Kadaikos.
Alternatively, think of it as
primary and
secondary tracks where a primary track plays once, while secondary plays in a loop. Maybe that's what Dana DiAnda was trying to do, as most of his tracks have parts one and two. It doesn't even always have to be a mystery ambient track as a secondary, as long as it's a kind of version that works well in a loop.
Think of your favorite TV shows. Typically, they'll have a main theme of some sort, usually sounding somewhat epic. As you watch the actual episodes, you can hear many different versions of the same theme playing slower or faster, in minor or major, depending on whatever is going on at the moment. A similar approach can be taken with various themes in a game.