Yes, that’s pi as in 3.14. One of the frequent questions that comes up in my work involves confusion over whether facts and data are subject to US Copyright: they are not. Original expressions or arrangements of facts can, however, be subject to copyright protection. A recent case helps make the distinction clear – and also shows how the same facts can result in completely different and wonderful expressions. In  Erickson v. Blake  a composer created orchestral work called ‘Pi Symphony’ based on the number pi (3.14). Erickson assigned a musical note to each digit between 0 and 9, arranged the work based on the order of the digits in pi, then registered the work with the US Copyright Office in 1992. Nearly 20 years later, Blake posted a video on You Tube called ‘What Pi Sounds Like.’ Blake had also assigned notes to each digit and arranged them based on the digits in pi. While the overall technique was similar, the results were entirely distinct. Erickson sued Blake for copyright infringement. Blake’s motion to dismiss was granted by the court (Blake ‘won’). The court looked at whether  the two works – each based on pi – were both objectively and subjectively similar.  The court found that Erickson was only entitled to ‘thin’ copyright protection because the number pi is a fact and arranging musical notes around pi is an idea. Any similarities between the works were due to the pattern formed by the digits in pi – which is not copyrightable. Take a few minutes to listen to each piece. Each is unique (and a pleasure to listen to), and they demonstrate how the same facts can be used to lead to very different kinds of expressions. They also demonstrate why ideas, facts, and data are not eligible for copyright and how, similarly, the promise of the public domain is fundamental for new, innovative creations. Listen at:  What Pi Sounds Like and  Pi Symphony: The Ruse Performance Movement I.