Can be done... look for the directory where the mabinogi-files are stored.
It should be either under the Nexon Launcher layer or beneath Program Files with /mabinogi/appdata/mp3 within.
The intro-music is usually the intro.mp3 file amongst a comprehensive list of other music-files.
Over-writing the intro.mp3 file will play what-ever other song/music you decided to rename into intro.mp3 to over-write the default.
This can also be done with just about any other of the back-ground music-files, but if you ever run into errors with the game/system, and use its file-integrity checker tool, such as from the Nexon-Launcher, everything will be reverted back to their exact defaults.
Everyone else will still hear the same default-music unless they've done similar to their mp3-files.
I have «re-mixed» versions of several different Mabinogi back-ground-music-scores but not for all of them...
(I think I may have lost a bunch because of a previous hard-drive crash when I worked the disk way too hard for too long...)
Here is an example of one of the music-tracks that I made a remix-version of from the arena_lobby.mp3 file...
Hey Kyrios, maybe you can ask the appropriate people why they keep giving us trashy, mathematically impossible coin shop events where getting one reward automatically locks you out of most of if not all of the others. No one likes this, no one thinks it's fun, and it basically defeats the purpose of even having an event in the first place (indeed, you could easily argue that no event is better than one that can't be enjoyed).
By my calculations, assuming we get the August update august 6, and get to rank 1 in all of the new skills, we should be able to gather 5,505 coins by fulfilling all of the daily and weekly. In order to get one copy of each of the permanent rewards, we would need 12,650 bell coins, and that's not including the relatively important scroll trade unlock valued at 2000 coins or the 1800 and 100 coin totems that have random rolls. We can get at most two out of three homestead figures, which people love even when they don't have stat bonuses. Or if we want an outfit, we probably have to sacrifice one of those figures. Except if we want a title, then we gotta change which figure or maybe don't get the outfit. Oh but what if we want to try to get one of those totems? Then we have to give up all the other rewards and hope we get lucky, or hope we get extremely lucky and then we could have a shot at an outfit or a homestead figure or a title.
A player should not have to maintain 3-4 accounts to max out event activities on just to get one set of unique event rewards. This is, by definition, bad design.
Through diligence, if I run on 4 accounts for myself, only ranking the skills on my main, and just doing repeatables on the others, I can expect to get one full set of outfit parts, homestead figures, the title, and then a few (2-3) scattered attempts at Pinkie's Note Box, and some tries at Katell's Small Rock Box. Trash like this is one of many reasons people don't want to play this game anymore, year after year of events that are impossible to fully collect or require a choice between 1 or 2 unique collectibles or the others.
Maybe you can ask them to start thinking about what a player wants to do instead of finding ways to inflate metrics like total active accounts, total log-ins, or total concurrent users.