That doesn't sound like what I meant. The point of image pyramids is that they separate fine details (e.g. style) from coarse details (form). A note transposed

That doesn't sound like what I meant. The point of image pyramids is that they separate fine details (e.g. style) from coarse details (form). A note transposed down an octave is still exactly the same type of object; it's not more abstract so frequency is not an analog to scale in images. What you want is a progression of abstractions, e.g. note, chord, melody... but one where 1) each is largely orthogonal so that they can be separated and recombined with a lot of flexibility (definitely not true of notes and melodies) 2) it be computed straightforwardly, preferably by a differentiable function 3) can separate style and form.