The Harmonic Series

File Festival

Created by Manuela Donoso and Luisa Pereira, The Harmonic Series is a collection of mechanical devices , software, sculptures and prints that explore the relationship between musical and visual harmony.Inspired by the nineteenth century mathematician Jules Lissajous who invented a device to visualize sound vibrations using two tuning forks and a beam of light reflected from one mirror to the next to a screen, Manuela and Luisa have re-created and extended this experiment using recent tools. An electronic version of the device replaces the tuning forks with microphones and speakers, allowing people to sing different musical intervals, and contrast the resulting figures with the more chaotic ones generated by percussive sounds. An application plays groups of three notes and plots 3d Lissajous figures for their frequency ratios. The frequency ratios for major, minor and diminished chords are 4:5:6, 10:12:15 and 20:24:29 respectively. These chords were plotted using the app, and then printed as posters and sculptures that reveal a tight relationship between aural and visual harmony.