I know everyone and their mother has talked about the music in this series but I've been wanting to make a post about it for so long so here we are. To all the composers involved in this project, I love you all so much.
One of the music producers at Riot said during a conference that many of the characters have a theme of their own, and other interesting things about Zaun and Piltover having a different musical "footprint", and how they bleed into each other during season 2 (!), and I think we can all agree that Viktor's theme is the single most recognizable character theme of them all.
(Very easy to spot here at 0:36, during the Toy Boat flashback)
At the beginning of season 1 we hear it often, loud and clear and happy, resolving in a major key ("It's Viktor" 1:00 ; "Our Hextech Dream" 0:45 ; "They think, they adapt" 0:11).
As the season progresses, and so does Viktor's condition, we stop hearing the major key resolve in the second half, keeping a gloomy, minor key tone.
(1:35, when he faints in the lab)
As far as instruments go, there isn't an instrument associated with any particular character: most of the time we'll hear strings, or brass instruments, for pretty much everyone.
There is however one exception to this:
The only "character" defined by a choir.
The first time we're introduced to the arcane is in Jayce's flashback with the mage, where a choir (with no particular melody yet) plays some notes in the background throughout the scene.
We can hear Jayce's theme too here (1:46)! His theme is much harder to spot, I personally have heard it in only two tracks. :')
The second, as expected, is with the Hexcore.
Towards the beginning, from about 0:14, we hear Viktor's theme again, but this time it is sung by a choir. Viktor's blood has already merged with the Hexcore, a part of him already lives within it.
And as if the foreshadowing wasn't enough, this is the image on the screen while it plays:
Heimerdinger's vision of the dangers of Hextech, the "magic in the wrong hands" he was talking about at the beginning of the season, framed in a blood red galaxy.
The best example of this is this track, Viktor's final experimentation and Sky's death.
Right at the beginning we hear Viktor's theme sung by a choir, then by a violin (0:19), and then by a choir again (0:33). A classic call and response, a dialogue between the Hexcore, literally calling Viktor's name, and Viktor's humanity (symbolized by the analog instruments) singing back.
Interestingly, in the "Am I interrupting?" scene, we hear Viktor's theme sung by choir again when he's reminiscing over Sky's death (0:36), but it switches to a violin whe he decides to jump: one last choice made as a human, against the Hexcore.
We hear Jayce's theme here too (1:01)! It's suble, and in a minor key, as opposed to the hopeful major key of his childhood, played by a viola perhaps? It sounds like something with a deeper timbre than a violin.
Now here's what caught my attention:
In season 2, we almost never hear Viktor's theme. At all.
The only very, very few times it appears is through Jayce's perfective, and always faintly, quietly, in the background: when Jayce fuses him with the Hexcore, when he says he's alive and stable in the hexgoop, and once more even more faintly when Viktor wakes up and Jayce says "You're alive!", but when Viktor is alone? Never.
And it makes sense: to Jayce Viktor IS alive, he can't allow himself to think otherwise. But is Viktor... Viktor? Because the only thing we hear in Viktor's presence, is a choir.
All of his tracks from season 2 are variations of different choir melodies, though never his own.
Until, of course, the end of the season.
After Jayce's speech, as soon as he touches Viktor, the erratic music melts into a fantastic, triumphant arrangement of Viktor's theme, which is not only in major key, but played by a violin.
There is no choir anymore. Whatever influece the Hexcore had is gone. With one touch, Jayce brought back not only Viktor's happiness, but his whole humanity.
There is so much more to say about the music in this series, and I haven't even discovered the other characters' themes yet...! Maybe all of this was obvious, but I had to put it in writing, even if it ended up being a super long post and maybe not too easy to follow :') Thank you so much for reading until the end!