What "Virtual Choir" producer worked with British composer Guy Sigsworth? 
Guy Sigsworth: Guy Sigsworth is a British composer, producer and songwriter. 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. Eric Whitacre:  He is also known for his "Virtual Choir" projects, bringing individual voices from around the globe together into an online choir.
i don't know