Feedback is central to much of DSP (the exception being feed-forward filters). If you recursively feed the output of a process back into its input, possibly with modification, much complexity is possible. This is, of course, the mindset behind maths results such as Cantor's diagonalisation and Turing's result on the halting problem (this latter one theoretical stuff from the early twentieth century that laid the foundations for modern computation). I'm wondering about using clever recursive feedback tricks to generate interesting music for demos without using much code or having too much precomputed data.
(My academic background was the crazy end of maths: things like model theory and especially nonstandard models, so I tend to live outside the box of normality rather than occasionally think there, so I often have a hard time expressing what I think would be interesting.)
I've kind of wandered off this idea for a while, but it keeps coming back to me, so I will most likely revisit it at some point.
