So considering you can't add 'MediaEffects' to the atmospheric area and have it read it...at all, I tried tucking it into the "JumpInMediaEffects" component instead - as this will cause the music to automatically start when you start a new game - while if playing from a save file all you have to do is jump to any sector to have the music start playing.
AddTo = "<ships/base_ship.txt>/FtlEffects/JumpInMediaEffects"
But, I got:
Unable to find node at path "Type" relative to "<(...)\mod.txt>/Actions/1/ToAdd"
no matter what I tried.
I'm guessing this is intentional, just a proper error message hasn't been made yet, i.e. it's a protected area, considering that when I changed the file path for the AddTo/OverrideIn/e.c.t. to anything else (basically) it would not come up with that error message. If it isn't intentional, i'd hazzard a guess that it's because the component is required to something else, given if you do
Action = Remove
Remove = "<ships/base_ship.txt>/FtlEffects/JumpInMediaEffects"
Unable to find source for non-optional field "JumpInMediaEffects" in
Even if you try to re-add it 1 line after.
I also got the same thing when trying to add a new trigger to a vanilla item, having the path point directly to "Part/Component".
I could add a single custom block for the music, even with it automatically moving to the next song, but it would be too similar to already existing mods. Hence why I'd rather not.