Why violin makers adopted the f-shaped hole

violin flow velocity

Why did violins slowly develop f-shaped sound-holes? Because it makes them more acoustically powerful than their ancestors, which had holes shaped liked a circle -- as a team of MIT scientists recently concluded.

Back in the the 10th century, the makers of European stringed-instruments were building "fitheles" -- the ancestor of the modern violin -- but they used round holes. By the 12th century, they'd started using half-moon shapes, and a century later they'd refined it to a sort of C-shaped hole. Then in the 15th century they pioneered little circles at the ends of the holes, which, by the 17th century, had become the modern f-shaped hole.

A team of MIT scientists recently wondered why the shape had evolved that way. After crunching the math and doing some experiments, figured it out: The f-shape turns out to have physics that push a lot more air than a circular hole, making the violin's output dramatically more powerful. From the Economist:

The entire paper by the MIT team is online here and is pretty interesting too. That image above shows the gist of what's going on: You can see how the f-shape drives much more air-flow than the round one, with high air-flow marked as yellow and red. Below, an image from the paper showing the increase in power as the shape changes over time.