In 2010, classical composer and conductor Eric Whitacre led a virtual choir of 185 singers from around the world to sing Lux Aurumque. He recorded a video that shows him conducting the song. The singers used his video to sing and record their part of song individually. Then they uploaded their contributions to youtube.

Now, in 2011, Eric did it again :) He conducted a virtual choir of over 2000 voices singing Sleep. The virtual choir video is not online yet (as of 2011-04-04).

But his TED talk video contains teasers in addition to some very entertaining background stories. Watch it!