James and Caitlyn Harrison

James and Caitlyn Harrison (sometimes James and Caitlyn) is the songwriting partnership of brother and sister musicians James Harrison and Caitlyn Harrison (both b. February 6, 1977) of Celestial Sphere. They are known as one of the most successful writing partnerships of music history and the most successful in the modern era, primarily writing for their bands Celestial Sphere and X Operandi, they also have written songs for numerous other musicians. As a duo they are credited with around 700 million sales, 550–600 million with Celestial Sphere around 30–40 million with X Operandi and 50+ million for other artists.