So this harkens back to a theory I did a long time ago explaining the possible effect on the mind of a listener, where the said effect would be that the mind would suppress any forced hypnotism or control over it and replace the "memory" of hypnotism to the song, as I pointed out that Cap'n Cuttlefish heard Agent 8 humming the song while unconscious, meaning this is the most current thing Agent 8 remembers and also why it is played when fighting Inner Agent 3, which is a theory all of its own that I will probably do later. With the longest introduction to my theory out of the way, here is the theory explaining the mystery of Splatoon's lore's most important song!
So far, only remixes of Calamari Inkantation was heard. Although, the original name of the song is actually Chorus of Calamari County or in the case of the game's European version: Calamari Shanty. This song is actually quite old according to in-game lore, so old in fact, that an original recording might not even exist. Well, the original recording is implied to have been done on a beach, as we can hear waves.
But due to the voices speaking in their own language, that might not even be the original recording either as the original recording of a song wouldn't have talking unless it's part of the song itself. However, I think we can figure out how old is the song, it's not specific but can give us an idea. When Octarians hear it, they break out of their mind-controlled state, so their ancestors, possibly being only Octolings at the point of their evolution being finished, had to have been amicable with Inklings at some point for the song to have such a big effect on them that would free them from mind control.
It's very possible that due to the song being played over many generations, both Inklings and Octarians had the song etched into their DNA, because if not, then it wouldn't have broken the mind control being placed on them. Heck, maybe that's the reason why it "frees their souls".
So far, only remixes of Calamari Inkantation was heard. Although, the original name of the song is actually Chorus of Calamari County or in the case of the game's European version: Calamari Shanty. This song is actually quite old according to in-game lore, so old in fact, that an original recording might not even exist. Well, the original recording is implied to have been done on a beach, as we can hear waves.
But due to the voices speaking in their own language, that might not even be the original recording either as the original recording of a song wouldn't have talking unless it's part of the song itself. However, I think we can figure out how old is the song, it's not specific but can give us an idea. When Octarians hear it, they break out of their mind-controlled state, so their ancestors, possibly being only Octolings at the point of their evolution being finished, had to have been amicable with Inklings at some point for the song to have such a big effect on them that would free them from mind control.
It's very possible that due to the song being played over many generations, both Inklings and Octarians had the song etched into their DNA, because if not, then it wouldn't have broken the mind control being placed on them. Heck, maybe that's the reason why it "frees their souls".