This is something that I was wondering about and wondered how the arrows and harps bombardment functions of curiosity since I'm replaying FFIV. I've check the boards and I didn't find anything about it, or I might of missed it. I don't know if this was already research or not, so sorry if this has already been answered and please re-direct me to that thread.
I remember a while ago... well, more like 10 or so years ago. I hack Edward's attack stats and gave him a lot of attack power (probably the maximum) and when I attack with his harp (Lamia's Harp). It took quite a long time before Edward finished his attack, the enemy was bombarded with music notes and it seems to never end. Also, the same thing happens with arrows.
There's something that I notice, the more arrows and music notes that were present, the more damage both of these weapons dealt. I've recently heard that more arrows/music notes appears when agility/speed increases meaning the more damage these weapon inflict. I have not tested this myself (the agility/speed thing), but I do know that the attack power, thru level ups and equipping new harps increases the music note's count.
We have EVEN MORE themes now, but some old ones are gone...