AnalogDiehard writes: A copyright case alleging infringement of a 1992 Lars Erickson song "The Pi Symphony" by Michael John Blake's "What Pi Sounds Like" was dismissed by US District Court Judge Michael H. Simon. Both pieces were conceived by assigning numbers to musical notes, then deriving a melody based on the pattern defined by a finite set of numbers in Pi. Judge Simon wrote in his legal opinion, intentionally announced on Pi day (3/14), that "Pi is a non-copyrightable fact". While the Judge did not invalidate the Erickson copyright, he ruled that "Mr. Erickson may not use his copyright to stop others from employing this particular pattern of musical notes". The judge further ruled that the two pieces were not sufficiently similar — for instance, its harmonies, structure and cadence are all different.