Often we celebrate the number pi -- ratio of the circumference of a circle to its diameter, an infinite non-repeating decimal that begins with 3.1415926535 8979323846 2643383279 . . .. Pi is a bridge between day-to-day mathematics that nearly all of us know and mathematics that is complex and difficult.
My own celebration of Pi includes these earrings -- but I have friends and former colleagues in the Bloomsburg University Department of Mathematics and Digital Sciences that celebrate Pi in a far more entertaining way -- in song. Here is a link to the YouTube version of "The Pi Song" with lyrics by Bill Calhoun and Kevin Ferland and performed by "Professor Parody (Kevin Ferland). Performance credits are found here. And here is a link to some more details about the song.
Here is a link to a previous posting with more mathy song lyrics by Bill Calhoun.