"One Other" mentions 3 songs:
  - The Magic Wheel (Theocritus) - p. 33
  - "Hark Mountain song" - pp. 34-35
  - "Last Judgement Song" p. 43

The Magic Wheel

"... it is the bones of JOHN that I trouble. I for JOHN burn his laurel.
Even as it crackles and burns, even thus may the flesh of JOHN burn for me.
Even as I melt this wax, with ONE OTHER to aid, so speedily may JOHN for love of me be melted.
Thrice I pour libation. Thrice, by ONE OTHER, I say the spell.
Be it with a friend he tarries, a woman he lingers, may JOHN utterly forget them.
This from JOHN I took, and now I cast it into---"

Perhaps less a song than ancient verse, this ritual was chanted by a woman who later identified herself as Miss Annalinda in an effort to get John to love her. After using the spell to draw John in, Annalinda has to pay One Other, a creature that lived in the bottomless pool atop Hark Mountain, for the spell. You can read the original Ancient Greek spell in its entirity here.


Hark Mountain

"Way up on Hark Mountain
I climb all alone,
Where the trail is untravelled
The top is unknown."

"Way up on Hark Mountain
Is the Bottomless Pool.
You look in its waters
And they mirror a fool."

"You can boast of your learning
And brag of your sense,
It won't make no difference
A hundred years hence."

I can say with a fair degree of certainty that Wellman modeled this song after a version of the popular folksong Rye Whiskey/Jack of Diamonds/Rebel Soldier titled "Clinch Mountain" or "Way Up On Clinch Mountain." Like Roving Gambler, this is another song often made entirely of floating lyrics, but the main tie I see to the Clinch Mountain song is the final stanza. A 1905 transcription from East Tennessee finishes with the lines "You may boast uv yore knowledge / En brag uv yore sense; But 'twill all be furgotten / One hundred years hence." You can read more about the song here. Additional threads from Mudcat are too numerous to link.


Last Judgment Song

"Three holy kings, four holy saints,
At heaven's high gate that stand,
Speak out and bid all evil wait,
And stir no foot or hand..."

"The fire from heaven will fall at last
On wealth and pride and power,
We will not know the minute, and
We will not know the hour"

Of the songs from the book, this should be one of the easiest to find. Wellman (by way of John) credits the song to "old Uncle T. P. Hinnard" as a way to ward off any and all evil things of this world. Yet try as I might, I could find no specific references to this song, or any evidence that T. P. Hinnard was a real person.