I'm not too sure either but it looks like it produces LFO's. LFO is just a signal like a sine wave, square wave, sawtooth wave, ramp etc. I'm not too sure which ones the cp251 has. It also looks like you can patch certain sections of the cp251 to produce more original sounds.
This guy is feeding a wave into the cutoff on the mf101 and that's what produces the wobble around 1:00. Kinda sounds like a tremolo depending on the shape of the LFO wave. Then he starts patching stuff up on the cp251 and since I don't know what all the inputs and outputs are on the cp251 I have no clue what he's doing. I'm thinking the cp251 and the mp201 are pretty similar but both have different sounds you can produce.
http://www.youtube.com/watch?v=uxl_x...eature=related