Irregular repetition

I like when music brings back ideas at irregular intervals. One example I often think of is the irregular return of the I-IV-I cadence in Swim and Sleep (Like a Shark) by Unknown Mortal Orchestra. You get 6 beats and then the cadence (which lasts 8 beats itself), then 14 beats before the cadence, 6 beats before, and then 8 beats.

Swim and Sleep (Like a Shark)

Unknown Mortal Orchestra

I think this mechanism usually relies on the kind of rhythmic footing I was talking about yesterday. In Swim and Sleep, the rhythmic footing is the consistent two-beat subunit. That consistency forms the basis on which the irregularity is built.

You could still have irregular repetition in an environment that lacks any rhythmic footing, but it would stand out less, because presumably everything else would be irregular as well.