I see you're talking about orchestal music that seems to be a world apart from pop music instrumentation, both because there's less use of electronic sound gene

I see you're talking about orchestal music that seems to be a world apart from pop music instrumentation, both because there's less use of electronic sound generation and because chords are played yuxtaposing several instruments. About guitars, I can believe the bridge, or even finger pressure provide adjustement for individual notes. But if you're playing a chord, you just trust the frets, that are uniformly spaced, following the logarithmic scale.