I fell in love with Tolkien's song-battle contest between Sauron/Thu and Finrod Felagund in the Lay of Leithian, which I paste here for those who might be interested. It is grimdark, and not the light, airy stuff of the Hobbit.
I love that the contestants weave metaphors of the world into their songs, for better and for worse. The mention of the Noldor elves greatest evil, the slaying of their kin, comes back to haunt poor Finrod here, who ironically, had nothing to do with it and actually tried to stop it.
The set up: Finrod and 10 companions are helping Beren reach Angband, the equivalent of Mordor, and are magically disguised to resemble orcs. But Sauron/Thu has discovered there's something not right, and seeks to unmask what that is.
The poem begins with Sauron, who:
"He chanted a song of wizardry,
of piercing, opening, of treachery,
revealing, uncovering, betraying
Suddenly Finrod there a-swaying
sang in answer a song of staying,
resisting, battling against power,
of secrets kept, strength like a tower,
and trust unbroken, freedom, escape;
of changing and of shifting shape,
of snares eluded, broken traps,
the prison opening, the chain that snaps.
Backwards and forwards swayed their song.
Reeling and foundering, as ever more strong
Thû's chanting swelled, Felagund fought,
and all the magic and might he brought
of Elvenesse into his words.
Softly in the gloom they heard the birds
singing afar in Nargothrond,
the sighing of the sea beyond,
beyond the western world, on sand,
on sand of pearls in Elvenland.
Then the gloom gathered: darkness growing
in Eldamar, the red blood flowing
beside the sea, where Noldor slew
the Foamriders, and stealing drew
their white ships with their white sails
from lamplit havens the wind wails.
The wolf howls. The ravens flee.
The ice mutters in the mouths of the Sea.
The captives sad in Angband mourn.
Thunder rumbles, the fires burn,
a vast smoke gushes out, a moan
and Finrod swoons before the throne.
Yet not all unavailing were
the spells of Felagund; for Thû
neither their names nor purpose knew.
These much he pondered and bethought,
and in their woeful chains them sought,
and threatened all with dreadful death,
if one would not with traitor's breath
reveal this knowledge. Wolves should come
and slow devour them one by one
before the others' eyes, and last
should one alone be left aghast,
then in a place of horror, hung
with anguish should his limbs be wrung,
in the bowels of the earth be slow
endlessly, cruelly, put to woe
and torment, till he all declared.
Even as he threatened, so it fared.
From time to time in the eyeless dark
two eyes would grow, and they would hark
to frightful cries, and then a sound
of rending, a slavering on the ground,
and blood flowing they would smell.
But none would yield, and none would tell."
https://thainsbook.files.wordpress.com/2015/07/the-lay-of-leithian.pdf