As you might recall from math class, pi is the ratio of a circle's circumference to its diameter. This irrational number—approximately 3.14159—shows up quite frequently in many mathematical applications, including geometry and trigonometry.
The first attempts to calculate pi can be traced back to ancient Babylonians, who calculated the area of a circle as three times the square of its radius, making the value of pi equal to 3. One Babylonian tablet indicated they got as close as 3.125 and later calculations by the ancient Egyptians (ca. 1650 BC) approximated pi as 3.1605.
The number today is celebrated around the world on March 14, which when written out numerically is 3.14.
On YouTube, Michael Blake decided to pay tribute to Pi. By assigning a number to each musical note, he was able to create a composition by playing out the digits of pi. View the video of his piece below.
Read this next: Mysterious Stone Circles Found In The Middle East