I love this video about dissonance in #music. I knew about overtones and harmony and timbre, but I never knew that different instruments can create entirely different series of overtones.
I suppose that explains why carillons have often felt weirdly out of tune to me.
And I've learnt that low and high #piano strings have to be tuned slightly off pitch to make sure that their overtones line up with the strings in the middle. And that this need is lessened when the strings are longer, which is partly why grand pianos are valued more than upright pianos.