just a little addition ive come to understand from comments underneath these themes!
other people have pointed out that there are two morse code phrases being played. there is the SOS signal, but there is also one that is … .- -.. (SAD). while there is no concrete evidence i can find for this, but comments have said before that SAD stands for Search and Destroy, meaning its probably the calamity itself fighting back
the SAD code is in every Divine Beast theme as an opposition to SOS, and this is shown by the fact that the codes are always in opposite ears, and are normally defined by different pitches.
Vah Ruta: the SAD code comes in first, low on the right, while the SOS code comes in right after it, high on the left. the entire time the codes are playing, the SAD code always comes in before the SOS code, often overlapping it. it would be hard to hear the SOS code at all if it were not a higher pitch
Vah Rudania: the SAD code comes first by just the slightest bit, high on the left, and the SOS code is low on the right. once again, the fact that the SAD code comes first makes it overlap the SOS code, except now the SAD code is also higher pitch. however, both codes are inevitably overwhelmed by the Divine Beast theme itself. Vah Rudania’s theme is so overpowering that we can only get glimpses of the codes
Vah Naboris: SOS is actually the first code to come in, high on the left, while SAD is low on the right. however, even though SOS is high and comes in first, it is very hard to hear over the opening chord (as OP said, its the faintest of all). SAD is actually much clearer than SOS. SOS is covered by little melodic themes on the left, while SAD is basically alone on the right
Vah Medoh: the first noticeable thing is that Revali’s SOS takes 15 seconds to come in, high on the right. SAD comes in later, low on the left. the codes are the most separated in this theme, clearly going one after another. it’s not until the 30-second mark that the codes begin to overlap, the SAD interrupting the SOS.
honestly examining these themes and their significance and little cues is really amazing. the amount of thought that went into them, the fact that the morse code was included in the first place. if the SAD meaning Search and Destroy is true, it is another heartbreaking detail that was not needed, but adds so much to the music and to the story.
(if it isnt Search and Destroy, or it isn’t SAD, i do wonder what that opposing code is, because its very obviously there)
maybe we’ll get an insight into the four champions battles and final moments in age of calamity, and if so, i hope that they include the morse code, even if it is just in the music again. it added so much to the atmosphere of the divine beasts, even if it hadn’t been consciously noticed at first, it is there, adding to the unease and sorrow of the divine beasts.
