Take a listen and look at this contemporary classical work for virtual choir which was made by letting people sing individual parts and film while singing and add it all together to a virtual choir: Eric Whitacre's Virtual Choir - 'Lux Aurumque' - YouTube .
This music simply gives me the chills… :a0 :a0 :a0 O0
A little on how they made this happen: The Virtual Choir: How We Did It