Persona 3 FES ADX file Question

[Century_]

So I'm making a persona 3 FES music mod and while I was browsing the BGM folder I found some duplicated adx files. The one i'm interested in is the file that contains the song "deep breath". But both 20.ADX and 23.ADX contain this song. So I was wondering if These two adx files are used in the two different scenes where deep breath plays. If so, which one plays in the full moon boss event and which one plays in the beach event? cause I think I could use two different songs for each. Also if anyone knows what the other duplicated files do and what the difference between them is, I also wanted to know what the difference is between memories of the school and it's no beatbox version or at least where they play.
It would be great if you could let me know. :)

[Niopack]

Persona games like to repeat everything, even when is not necessary. Every time you found a duplicated file like that, I suggest you change any of both with the one you want and replace the remaining one with a placeholder, then test it. That's the best way to tell which is which.