The Mathematics Behind The Sound Of Music

There’s a lot going on between us and the music – good vibrations (and bad) interact through a complex combination of physics and biology to move the sounds we hear into our brain. Explaining it all in a rather dynamic and engaging way is Vi Hart…

Physics, Math, Biololgy – Sounds Simple

Sound is vibration, from the excursion of your speaker cones to the wiggling of the air molecules to the modulation of the Vasilar Membrane within your Cochlea.

But why do notes categorise themselves into octaves – or is this just an arbitrary human artifice? And why does this sound pleasant to our ears? As Pythagoras observed by shortening the length of a vibrating string in simple fractions – halving and halving again – octaves up represent a doubling of frequency, and other simple divisions (thirds, fifths) sound pleasant to us because they are both mathematically coherent, and compatibile with the way our inner ear works.

But I couldn’t explain all this quite as eloquently as Vi Hart…

If that’s not enough fractional activity for you, try some more mathematical music angles…