Visual Music is a means of expressing music in visual form requiring the active involvement of an artist, designer or director to interpret the music and find the means to express it visually. This is also where the word multimedia originated. Rock videos could be said to fall into this category but the most wonderful examples are more abstract and can be spell binding, awesome even. The presentation of a Pink Floyd concert is a perfect example of this second form . Visual Music has no relationship with music as such, although it maybe viewed with or juxtaposed with music.
Visual music is about creating visual relationships which change over time.
It is primarily about abstract qualities of movement or changing form or color. This is the kind of visual music closest to my own sensibilities, it is perhaps the most illusive or least understood form. The earliest proponents used mechanical or optical means. The first great creation of Visual Music to receive widespread notice by the public was the Stargate sequence in the movie 2001. In the 70s, artists like Tom DeWitt and Richard Monkhouse started creating special analogue electronic 'image synthesisers'.