My basic idea is a world with a “string theory” where the strings are actual metaphysical musical strings that manifest magical effects when “plucked” a certain way.
Ocarina of time but with strings?
Wouldn’t you go about it like any other world with magic? Just switch out the staff/wands with instruments(guitar/violin) and the gibberish words with melodies.
The notes played would resonate with the strings. Sounds pretty dope. Of course this is all more flavor text and in world mechanics.
Edit: not sure if this is for a story or ttrpg. Also, singing could cause resonance which adds more options
Check out the old Lucasarts game Loom. It’s an old-school graphical adventure where you interact with the world using music-based magic. It doesn’t go too deep into the actual mechanics, but it’s a great game.
I mean, that would depend on how everything interacts with those strings.
Are they everywhere and you just pluck them with your fingers basically in thin air? Then mages could just be shredding air guitars all day, which might be hilarious if thats what you want to go for.
Do the strings vibrate with every sound that is made? Then there could be different ways of doing magic. Instumental, singing, speaking, clapping, etc.
Is it only music? And would natural sounds also be able to cause magical effects? Or is physics even the other way around in your world? Do sounds just occur and the right whisper makes the trees sway and a loud rumble can make the earth quake?
From there you could get into a Tolkien-like area, where the world was just sung into being in the first place.
Just to throw a few questions/ideas out there, where this might go.
Sympathetic resonant induction. The interaction of frequencies is the underlying principle of both string theory and music theory. Assign various “flavors” of string which resonate with different elements/colleges/domains, spells sung or played properly in tune manipulate the fabric of reality.
Develop a musical language, look into Solresol and Enochian for some inspiration. Include monasteries with gongs and singing bowls, church organs, choirs, anything like that. Religions lean heavy into “the Word”.
I would definitely involve the Tritone, a chord that was considered evil by the church
Reference Kung Fu Hustle:
Or Multiverse of Madness:
The anime Takt op. Destiny is pretty aligned to this concept as well
Check out the Songs of Roshar in the Stormlight Archive by Brandon Sanderson. But I guess this is a loose fit as magic exists without sound in the universe.