Free running phase locked multisamples?

How difficult would it be to build an ensemble that uses chromatic looped multisamples as free running. per-key oscillators and that maintained phase synchronisation between notes of integer octave interval?

So, pressing a key would open a gate on the looped sample for that key - but being free running the loop would not start from a fixed pos. at each key press. Pressing a key of same note value but in a different octave (for example, C3 and C4) would sound the loop for that key, but, importantly, both sample loops would be in phase (for a sine wave, two loops an octave apart would have two crossover points synced per complete duty cycle of the lower octave).