Composer/conductor Eric Whitacre has an official web site where he blogs. He explains how he made Lux Aurumque:
I made my own conductor track, filming it in complete silence, hearing the music only in my head. Then I watched the video and played in the piano accompaniment part to my conductor track...Then I offered the sheet music as a free download. As singers began posting their individual tracks, I called for ‘auditions’ for the soprano solo...He goes on to talk about how it was put together and his hopes for future projects.