I have spent a lot of time thinking about the use of random choice in computer art. I have been using random numbers to create art since my days at CalArts. The very first useful computer program I wrote (in BASIC on a Timex Sinclair) computed tables of random numbers for the purposes of being used in music compositions, after the manner of John Cage.
A great deal of the software I have made, especially the recreational software, such as the puzzle generators that are used for krazydad.com, make heavy use of random numbers.
It is perhaps worth pointing out that the use of random numbers does not agree with everyone.
John Whitney’s experimental films made use of sequences which were highly predictable. He slams John Cage a bit in his 1980 book Digital Harmony: On the Complementarity of Music and Visual Art saying that he understands Schoenberg when he said to Cage “you must have a feel for harmony.” Whitney’s movies have a high degree of apparent order to them, which would have been reduced if he had used random (or brownian) motion. He says that the movements “collect and release tension.”
In John Maeda’s book Design By Numbers, he very briefly touches on the use of randomness at the very end and then goes on to say:
…the outcome is difficult to predict, which seems to be the whole point of using random numbers. There are many better ways to become completely lost in systems of noise, and if this is the path you wish to pursue, then I hope you get lost in earnest.
Wow, harsh words! In both cases, I think these two Johns (Whitney Sr. and Maeda) are confusing one potential *reason* for using random numbers (i.e. giving up choice) with the use of the numbers themselves. There are many possible reasons for using random numbers – and we can choose precisely how much choice we wish to give up: a lot, a little, or none at all.
When Maeda says “the outcome is difficult to predict” he is implying “the outcome is difficult (for me) to control.” But random numbers can indeed be used in a controllable (and predictable) fashion. Just as an artist can control an airbrush to produce relatively specific results, so can a stream of random numbers be manipulated to produce very specific effects. The users of random numbers do not necessarily intend, as John Cage did, to “deny the ego” – to give up control over the outcome.
Although the first music I wrote using computer-generated random numbers was very much in the spirit of John Cage, the subsequent music was not – it was more in the style of Lejaren Hiller. I used random numbers to generate notes, but then I *sculpted* those results, by running them through the rules of species counterpoint to create music with recognizable western harmonies and rhythms. The rules acted as a kind of filter, just as the nozzle on an airbrush controls the flow of paint.
Similar my puzzle generators are a kind of filter -- I think of generating puzzles as a bit like panning for gold. There is a flow of interesting stuff coming downstream, and I am looking for the gems amongst the dirt and rubble.
Random numbers generators are simply a tool – and a very powerful one at that, as anyone who has written a Renderman shader can attest!
One of the reasons that I like making kaleidoscope simulations is that the kaleidoscope is a perfect illustration of the fusion of randomness with predictability, and the interesting things that can happen when they meet.