From the Worm Ouroboros, by E. R. Eddison, which I have recently been re-reading. I love that book and it is, no doubt, one of the greatest books of fantasy/myth ever written. Pure poetry in prose, and often, outright song:

She took the heavy volume with its faded green cover, and read: “He went out on
the night of the Lord’s day, when nine weeks were still to winter; he heard a great
crash, so that he thought both heaven and earth shook. Then he looked into the
west airt, and he thought he saw hereabouts a ring of fiery hue, and within the ring
a man on a gray horse. He passed quickly by him, and rode hard. He had a flaming
firebrand in his hand, and he rode so close to him that he could see him plainly. He
was black as pitch, and he sung this song with a mighty voice–

Here I ride swift steed,
His flank flecked with rime,
Rain from his mane drips,
Horse mighty for harm;
Flames flare at each end,
Gall glows in the midst,
So fares it with Flosi’s redes
As this flaming brand flies;
And so fares it with Flosi’s redes
As this flaming brand flies.

“Then he thought he hurled the firebrand east towards the fells before him, and
such a blaze of fire leapt up to meet it that he could not see the fells for the blaze. It
seemed as though that man rode east among the flames and vanished there…”