Strauss's tone poem has become well known, both in the concert hall and through its use in the science fiction film 2001: A Space Odyssey. Strauss's source, however, has a much deeper history. This source was a novel by the philosopher Friedrich Nietzsche, which fictionalizes and reevaluates the philosophy of Zarathustra (also translated as "Zoroaster"), a philosopher and religious mystic of the late 7th century BCE. Zoroaster, who lived in Ancient Iran, made a comeback in Enlightenment Europe, where his non-Abrahamic theology influenced the development of Deism. Zoroaster is also frequently acknowledged as a precursor of the esoteric, or magical tradition of knowledge-which made his name useful in the theater for a stock "magical" character. Handel's Orlando features a "Zoroaster," and Mozart's "Sarastro" is only a few letters off…