I'm not familiar with the minutiae of of piano tuning, but nothing prevents you from tuning your piano keys so that F# and Gb are two different keys. The only reason why they're the same key is because we use an equal temperament tuning. Of course, if you tune the flats and sharps separately, then the range of your piano would be considerably reduced.
And yes, fretless instruments such as violins can be precise enough to differentiate between the two.
Re:Music theory for nerds (2016)
by AlbertCory on Saturday February 19, 2022 @11:02AM
(#30398061)
> nothing prevents you from tuning your piano keys so that F# and Gb are two different keys.
"nothing" other than the fact that there's only one black key which has to serve both purposes?
They're the same on an instrument that can only play a defined set of notes, e.g. a piano or fretted instrument. It has nothing to do with the piano being in equal temperament.
If a violinist is playing an F#, his finger isn't necessarily on the exact same spot as when he's playing a Gb. As he explained answering my question, it isn't even in the exact same spot for the same F# every time in the same piece. The string players have very slight variations that they can describe precisely to each other so they sound good together.