EDIT: Nevermind, I see what I did wrong, I had Perfect Unison as my second interval but had a brainfart and read it as perfect octave, solved the puzzle.
I don't want spoiled, but I'm currently in the Nexus of Technology and have cleared everywhere I can except the door locked by the Musical Cipher. I'm pretty sure i'm working through it correctly, but the decoded text I'm producing is gibberish, whereas it states in the terminal text that it was the names of musical pieces. Does this mean I'm likely making a mistake somewhere?
Additionally, when reversing the transpositions, if a note ends up on an octave not given by the octave numbers (e.g. after de-transposing it ends on octave 4 but I have octaves 3, 5, and 8 ), do I just treat it as being in the octave below the one I was transposing from (e.g. it was transposed from 5, ended up in 4, so I treat the end product as being in 3, which is before 5 in my octave numbers), or do I ignore it?
Finally, I've seen people mentioning a "Sonic Gun" as a reward for the cipher puzzle, I take it this is the intended method for dealing with the Naga at the entrance to the facility after power is on? Deactivating security and improving my security clearance with the severed hand doesn't seem to accomplish anything and the Naga is nigh impervious to damage.
For reference, I get F*AECFHHE0 for the first line, I stopped at the 0 as I assume this is the number hidden in the line I'm looking for, here's my notes and key:
