In Greek mythology, Helios is a Titan who faithfully drove the Sun's chariot across the sky each day, disappearing in the west into Oceanus (the ocean, which the Greeks believed encircled the Earth), and rising out of it again in the east the next morning. Helios' journey at sunrise is referenced musically by the ascending leap in the main theme and the strong driving rhythms of the low winds and percussion. The contrasting light and dark textures in the slow section depict twilight inevitably giving way to the darkness of night. (2:45).
