On 7 April, 2011, Eric Whitacre will release his latest Virtual Choir project, with the performance of his work, "Sleep." This project involved the participation of no less than 2,051 voices from 58 countries! In association with that event, Eric gave a TED talk in March, 2011 where he outlined some of his history and the inspiration which gave rise to his previous Virtual Choir project, "Lux Aurumque."
Here is the TED talk with a sneak preview of the first three minutes of a performance which I can honestly say is nothing short of BREATHTAKING!
And here is the complete performance of Eric Whitacre's Virtual Choir 2011 - Sleep: