In addition, I also tried adding the music from EB. I can't seem to find much information on modding music but I did manage to find this thread:
https://forums.totalwar.org/vb/showthread.php?t=53419
Quote Originally Posted by wlesmana View Post
LAST NOTE: If you've never modded the music before and you've just upgraded with 1.2 patch, there's a chance you have a file in Data/sounds folder called events.dat. This file is not really used by the game but it does overwrite any changes you made to desc_sounds_music.txt so if you find this file, just rename or dump it.
It is mentioned that events.dat can also be renamed or dumped, however as I have explained above, I will receive an error.
I edited descr_sounds_music.txt and changed the reference directory to data/sounds/music (I copied this from EB descr_sounds_music.txt). To be sure, I copied the music folder from RTW/EB/data/sounds/ into RTW/data/sounds/ as well as RTW/exrm/data/sounds/ . I even copied the events.dat from EB and removed both events.dat, events.idx however the same error will still occur. If both the files are not removed, the music will remain the same as the original game.

I hope someone could advice how to go around the error when i remove events.dat, or point out some mistakes I have made as I'm still quite new to modding sounds. I have experienced modding quite a lot of txt files with regards to units, buildings, ancillaries and other stuff, but I'm quite stuck with music as I don't find a lot of guides or threads on it. Thanks in advance.