What "Virtual Choir" producer worked with British composer Guy Sigsworth? 
Guy Sigsworth:  During his career he has worked with many artists, including Seal, Björk, Goldie, Madonna, Britney Spears, Kate Havnevik, Imogen Heap, Bebel Gilberto, Mozez, David Sylvian, Alanis Morissette, Eric Whitacre and Alison Moyet. Eric Whitacre: Eric Edward Whitacre (born January2, 1970) is a Grammy-winning American composer, conductor, and speaker, known for his choral, orchestral and wind ensemble music.
i don't know