2 in 1
The two musicians are in the same room. The room is separated into two parts diagonally by the projection plain. The audience /beholders should be able to walk round the stage.

2 in 2
The musicians are in two different rooms, e.g. two rooms next to each other, two places in the same city or even in two different countrys. Classical stage situation (stage in front, audience sitting). The music is transferred via Skype.