Out of more than a dozen composers considered for the job of writing the Assassin's Creed score, Jesper Kyd was the one who accepted the challenge of bringing the past and the future together in musical harmony. With a science fiction story set both in modern times and almost a thousand years ago, the job of marrying both very different musical eras and the mixture of cultures would prove difficult but ultimately rewarding. Kyd began initially by creating rules for himself to follow when approaching the composition of certain themes, particularly for locations.