There’s a photoset going around Tumblr showcasing some photos of the insides of musical instruments. Let me share a small piece of the genius behind a violin’s design.
I’m going to tell you about something called a sound post.
Inside every violin, viola or cello there is a narrow little wooden dowel. It rests inside the instrument, propped between the front and back plates. Its placement has to be perfect, meticulously set by a violin-maker in precisely the right spot, down to the millimeter.

A violin is such a delicate piece of acoustical engineering that a slightly offset sound post will leave the instrument’s tone sounding empty and hollow. It’s an unassuming, humble little piece of wood… with all the importance in the world.
In Italy the sound post is referred to as anima. In France it’s âme. Both words mean “soul.”
Let us consider the fact that sound posts are never really at risk of being dislodged. They are never glued in place because there is no need; the faceplate of a violin is under hundreds of pounds of pressure at all times, exerted by the tension of the strings. This is enough force to break bone, but a fragile violin weighing only a few pounds is built in precisely the right manner not only to withstand the stress, but to use it as an advantage. It is this same tension that allows the vibration of the strings to resonate through the body of the instrument, resound within it, spill into the surrounding air and ultimately reach our ears as song.
And artisans in candlelit workshops figured this stuff out centuries ago.