I fear it's always going to be something-centric though. I play the clarinet and there's simply no easy way to indicate which fingerings to play short of sketch

I fear it's always going to be something-centric though. I play the clarinet and there's simply no easy way to indicate which fingerings to play short of sketching a clarinet and drawing it out (which is what happens, very schematically). That said, it is remarkable how easy it is for a pianist to play on sight, whereas for classical guitarists that's usually only a skill you can hope to attain if you major in music. Banjo and ukulele are even harder, because of the re-entrant tunings where your highest note is the topmost one instead of the bottom one, destroying what little correlation there was left between sheet notation and hand/finger position.