From Music to Visuals – and Back 2D Fourier Transform applied on Music Piano Roll Plots

When a 2D Fourier Transform is applied to piano roll plots which are often used in sequencer software, the resulting 2D graphic is a novel music visualization which reveals internal musical structure. This visualization converts the set of musical notes from the notation display in the piano roll plot to a display which shows structure over time and spectrum within a set musical time period. The transformation is reversible, which means that it also can be used as a novel interface for editing music. The concept of this visualization is demonstrated by software which was written for using MIDI files and creating the visualization with the Fast Fourier Transform (FFT) algorithm. This software demonstrates the live real-time display of this visualization in replay of MIDI files or by music input through a connected MIDI keyboard. The resulting display is independent of pitch transformation or tempo. This visualization approach can be used for musicology studies, for music fingerprinting, comparing composition styles, and for a new creative composition method. Keywords-component; MIDI; music; visualisation; FFT; 2D Fourier Transform;