rhythm: loops, lfos, delays, frequency beats, start and complete decay of a repeatable action or gesture
pitch: filters, tape speed, feedback level/distance to speaker, pitch shifter
these are the common rudimentary musical elements in noise. I feel like there is a sense of timing of when things change in noise, japanoise especially. I know I try to hit different frequency ranges at different times at different qualities, in a vague pattern, vague enough not to be obvious.
I have to say the ones that defy this are vomir and jliat from creating stasis, no structure at all.