For a brief period in history, the 'Harmonograph' was a very popular attraction: a strange apparatus, composed of two pendula, pen and paper, slowly tracing a single line, ravishing guests of late XIXth century salons who would come home with a unique rendition of... whatever you think it is.
This computer version of the harmonograph recreates a more precise and high definition of the well-known Lissajous curves when resonating at harmonic frequencies.
Press 'S' on your keyboard in live mode to generate a 3600x3600 high-resolution image (it takes a few seconds).