Music for the battle arena, how to add new tracks.

There's already a guide on the topic of music: https://www.youtube.com/watch?v=xZcJHKFbBlI

Good afternoon!
I did mention in the post that I wanted to NOT replace anything.
But to add music to what already exists, as an addition. =)
These are still two different things.

The video you linked shows only how to replace things.