When Grainer first heard it, he was so amazed by her rendering of his theme that he asked: "Did I really write this?", to which Derbyshire replied: "Most of it". Grainer attempted to get her a co-composer credit, but the attempt was prevented by the BBC bureaucracy, which then preferred to keep the members of the workshop anonymous. She would not be credited on-screen for her work until "Doctor Who"'s 50th anniversary special, "The Day of the Doctor". Derbyshire's original arrangement served as Doctor Who's main theme for its first seventeen series, from 1963 to 1980. The theme was reworked over the years, to her horror, and the version that had her "stamp of approval" is her original one. Delia also composed music used in BBC programmes, including "Blue Veils and Golden Sands" and "The Delian Mode".