The capital letters in that font are used by the status text (HP, MP, LV) in the main menu for whatever reason. They had to be changed, otherwise I would've just left the original font intact.
Really I could just copy the entire menu font over the music player font and it would work, FF6 Advance did that, the only thing is the thin font really looks better there, it usually fits in the title box without the need for scrolling.