Wow, this is an old thread
But I still maintain my old view that "random" is merely unknown factors or factors calculated with inappropriate mechanics.
A good drummer is a fine example. Let's say he plays a beat in traditional 4/4 beat. It is easy to hear that the drumbeats are not random, they are all intentionally put where they are. Easy because you are measuring on the same scale as the drummer is playing. One, a two, a three, a four...
But lets say he starts playing a beat in 5/4. If you still measure on 4/4 time your prediction of where the drumbeats will bee becomes wrong. At first it will appear that he is just randomely hitting the drums, but if you keep measuring you will see that there is no randomness to it still. The cycle is just longer.
In 4/4 beat the cycle is just one count to four before the pattern repeats. For 5/4 the count is to five and then the pattern repeats.
But if he plays 5/4 and you count 4/4 the new cycle is the two old counts multiplied. 4*5=20 counts before the pattern repeats. (The song Seven Days by Sting is an example.)
Now, if the drummer is playing 13/7, and you don't know and don't have the ability to measure the correct count, you would have been unable to pick out the pattern. It would appear random to you.
And if the system in question is something much more complex than a drumbeat, and if we don't know the pattern we are attempting to predict it will seem like no pattern at all. Just randomness. To make sense of it we would apply different methods of discerning and predicting any event, making them recognizable and no longer random.
If our system of calculating this was nearly accurate, if it was 99% accurate, it would be pretty good at making predictions. But the final 1% accounts for randomness. Events we still lack the means to measure correctly.
In a drumbeat it would be one renegade sound repeating at intervals you are unable to predict even though you can predict all the other sounds in the beat.