Is it possible to route in an external signal and divide it down, kind of like the EML polybox? I heard from somewhere that the Oz can do that or is that a myth? How about the Stringz?

The divider used to produce the tones in the Oz and Stringz-n-Thingz normally gets its "clock" or steady stream of logic type pulsing at a MHz frequency range. It is dividing in a range of two to four hundred times, or so.

The EK-1 experimenter's kit manual, posted here, has details about top-octave divider ICs:

viewtopic.php?f=6&t=482

The Oscillator Divider for sub-octaves modification for FatMan shown here is an example of a way of "dividing audio signals".

viewtopic.php?f=15&t=238

Oz had an external audio signal input, but that was only for the built-in audio amplifier/speaker.

So.. could I technically throw a switch between the main oscillator and the divide-down circuitry and run the signal, say from a paia 2720 through said divide circuit and get polyphony out of it?

They're in very different ranges -- the MegaHertz, radio frequency, ranged clock to the top-octave divider IC and the Hertz-KiloHertz, audio frequency ranged waveforms of a synthesizer VCO.

It might be interesting though, using the divider outputs as event triggers with the abnormally low clocking into it from a synthesizer VCO's pulse output.

Polyphony would not be available by dividing the audio output of a VCO, only additional frequency content (sub octaves/harmonics).

hmm.. that kind of gives me an idea for a single vco "ring modulator", FM, or harmonic generator.