Music visualization is the electronic generation of shapes and images based on music, which allows music listeners to "see" the songs to which they are listening. The primary tool to create shapes and images through music visualization is computer software which is designed to capture data from a music audio file. For example, it gathers information about frequencies and volume levels, both of which can be represented numerically. The computer software then translates the data into a specific hue on a predefined color spectrum. It also assigns the data a spatial point using X and Y axes.
As the computer program receives continuous data from the audio file, it defines new colors and spatial assignments in real time. This "animates" the music, making the shapes and images change in sync with the audio. Music visualizations generally are quite complex because music is not just one data set. At any given point, for example, multiple frequencies and amplitudes can be present, and the program has to deal with as many as possible given the constraints of the programmer's software code.
A major characteristic of music visualization is that the visualizations are unique for every piece of music run in tandem with the visualization software. The visualizations differ from work to work because the data the software captures are never the same from song to song. Subsequently, part of the intrigue of music visualization is the fact that users of the software, who may have hundreds or even thousands of audio files to use, perceive the visualizations as exciting and fresh each time.
More broadly, music visualization also can involve the control of light via computer programs that capture music audio information. This works on the same basic principles as regular music visualization, except that instead of assigning the data to what amounts to a constantly evolving graph, it assigns it to specific light circuits and fixtures. The person using this type of music visualization typically has to provide the program with basic information about the lighting system to which the computer connects. This is a popular form of music visualization at concerts and similar shows.
Most commonly, people who want personal music visualization use the visualization programs on desktop and laptop and computer systems. Advances in technology mean that the programs also can be run on mobile devices such as cell phones, however. Additionally, manufacturers sometimes include stand-alone visualization applications in devices such as televisions so that consumers can visualize music from the shows they are watching or from music stations.