[hunter2_]

I know it's no problem for trained players, but I suspected that an instrument's ability to have its player worry about pitch exclusively on the fingerings might be what Quartesixte meant in their claim that a violin plays in all keys "naturally."

Interesting about woodwinds not being equally tempered! I see another commenter points out the same, so I take that back as an incorrect assumption. So I wonder why they wouldn't build them as such, given that it would reduce the worst-case required bending to achieve arbitrary-key just tuning. I think the octave key is typically the only critical use of the harmonic series (altissimo aside), and that's a perfect 1:2 in all systems so it's moot.

[quartesixte]

Yeah I guess what I was trying to get at is the instrument isn’t “naturally biased” towards a specific key in the same way woodwinds and brass instruments are.

[hunter2_]

But that's most true only if you forbid playing open strings. Or if you demand that they be tuned to equally tempered fifths rather than just fifths, and that the player finger accordingly! Neither is likely, in which case it's biased toward keys that include just-tuned open strings, and a player would need to make a conscious effort to avoid open strings when other key-appropriate intonation is desired. That leaves us with only keyboard/mallet instruments as being unbiased with respect to key, but their equal temperament isn't what I'd call natural nor what an orchestra ought to sound like overall (though they could be tuned with bias toward the keys being performed, to help blend with the orchestra...).

[bondarchuk]

I would not recommend retuning your marimba too often ;)