I remember when I had an EDP years ago it had a feature called Loop Windowing which originally had been a bug. It then became an "official" feature. If e,g, there had been a loop of 8 sec a "window" within this loop could be defined by pressing a switch to define the startpoint of the the "window" and then by pressing it again to define the endpoint of it – so there had been a new but shorter loop which contained material of the original loop. This new loop could either be looped, overdubbed, etc or the so defined LoopWindow could be moved forward and backwards through the original loop. A very creative technique.