Pi (π) is the number given by dividing the circumference of a circle by the diameter. The melody of the PI symphony is based on this number, with 1 being the tonic, 2 being supertonic, 5 dominant, etc.. A zero is a wildcard note, and the rhythm and accompaniment are simply written to fit the melody.
The piece comprises four sections, each containing 50 digits of pi, that is, 50 notes in the melody. Each section is in a different key, with the '1' note changing to reflect the key change. In the opening bars, the numbers are quite distinct.
π = 3.1415926535897932384626433832795028841971693993751058209749445723078164062862089986280 34825342117067982148086513282306647093844609550582231725359408128481117450284102701938 5211055596446229489549303819...
As written by Brendan Petty: The Pi Song (MP3), The Pi Song Sheet Music (PDF)
The Pi Song - Stage Band (MP3), The Pi Song - Stage Band Sheet Music (PDF)
As interpreted by Josh Rosens... The Pi Song - Techno (MP3)
Email brendanpetty@gmail.com.