The concept of virtual duos has been going on for some - since the rise of compressed music formats such as mp3, and the ubiquity of emails. I've done internet duets with people in the US whom I've never met face to face - and great fun they've been.

What's fascinating is the internet domino effect, where someone posts a piece of music which then gets downloaded, re-interpreted and uploaded elsewhere - to be downloaded and re-interpreted, etc. It happens all the time with all genres of music on YouTube, though mainly with popular, commercial material. Because of the spread of instant information to a wide audience, through the net, one could imagine a "folk process" taking place at high speed, with songs evolving at a rapid rate...