Each circle represents the prevalence of individual notes in each song. Each song is run through a music frequency analysis program that visualizes the frequencies being played and what note they correspond to. The percentage of a song employing a given note is calculated and graphed on a circle containing 100 concentric circles, each representing 1%. The highest note, B8, is located at the top. As you move clockwise the note gets lower until is reaches C2 back at the top. For example, in the first song, Concerning the UFO Sighting Near Highland, Illinois, the most commonly used note is G5, which is played approximately 58.1% of the song.
Note: The program was unable to analyze very high and very low frequencies. All data is approximate.