This improvisation takes it's cue from Isobel's practise of her grade 1 pieces which she recorded (it begins her playing, which I then take over). I suppose this is a type of participative online activity which I'm becoming very interested in.. particularly keen on the 'virtual choir' (see http://ericwhitacre.com/the-virtual-choir).
I see a relationship between activity and communication, where activity can change the way individuals 'position' each other through their communication (as according to Rom Harre's 'positioning theory'). This is close to what Boal seems to be suggesting when he tries to involve audiences in subverting dramatic action.
I tried some role-play with our Strategy Cascade conference yesterday. We provided a series of 'pen portraits' of difficult people in the institution, and asked participants to put themselves in the mindset of those people. Worked very well, probably because the positioning between the participants was altered through them playing a role.
Next stop: try this online, maybe in some sort of 'virtual theatre'...