Thank you for asking this question! (Not least because I am itinerant and my Borges is all in boxes, but your question led me to this collected stories of Borges in pdf, which will provide ℵ value on any mobile device.)
Borges was not only profound, he intended his stories to be enigmas. Any analysis I give can only be partial, and must be regarded as musings on certain symbols and themes, not definitive answers.
The story is quite ambiguous regarding identity: The black guitarist is never named, and it is unclear as to whether Recabarren is the narrator. This relates to a theme of the story in which all men belong to a single group. (In the linked pdf, you can find Borges using a form set theory in the context of narrative construction, and the narrative nature of reality may also be said to be a theme.)
Further support for "ambiguity of identity" as a theme may be found in:
- Recabarren regards a visitor at his door as: "A boy with Indian-like features (Recabarren's son, perhaps) opened the door a crack."
- Recabarren loses the ability to speak after the guitar player loses the singing contest and never sings after, suggesting the two are linked.
Exactly how that link is interpreted is multi-variant, and can be understood in contexts such as philosophy, literature, and psychology.
A very simple analysis of the story involves freedom:
- Recabarren is presumably bed-ridden per his "great useless body"
- The windows of Recabarren's room have heavy bars.
Recabarren is unsentimental: "He looked down without pity at his great useless body". Upon learning he can no longer speak, Borges writes "From
learning to pity the misfortunes of the heroes of our novels, we wind up feeling too much pity for our own; but not Recabarren, who accepted his paralysis as he had earlier accepted the severity and the solitudes of the Americas."
Thus, Recabarren both is trapped by his infirmities, but unbound by them. His minds is free, and he does not suffer, because suffering is a perceptual condition.
The face of approaching rider is unseen:
- "Recabarren could make out the broadbrimmed hat, the dark poncho, the piebald horse, but not the face of the rider,"
This, to me, suggests the rider may be Death, but I can only guess because the rider's features.
But per the story's reversal:
The black man (the guitarist) fulfills the function of the Grim Reaper.
Note that it is a knife fight, not a gun fight or other form of combat. Reaping requires a blade.
Ambiguity is in regards to the interloper who is given a name, Martín Fierro. ("Fierro" means "iron" and Martin is a form of Mars, god of war.)
- "His work of vengeance done, he was nobody
This indicates that identity comes out of having a purpose. With that purpose fulfilled, the actor gains freedom from self, in the profoundest sense.
This is reflected in Recabarren's equanimity regarding his own condition. However, for the unnamed man, this freedom may be illusory:
"Or rather, he was the other one: there was neither destination nor destiny on earth for him, and he had killed a man."
This is, again, highly ambiguous. Not "because" he had killed a man, but "and" he had killed a man.
Perhaps it refers to the status of Cain? Or that the character has no meaningful future because death is now impeding per his trade in identity with the other? Or that he has switched from "one with a purpose" who is an agent of destiny, to "one who awaits their destiny", which is a metaphor for dying. [Compare to Yeats' "The Song of Wandering Aengus" where fulfillment is creative death, and unfulfillment is life itself.]
The man is free because he achieved vengeance, but achieving it creates another prison. (Although, perhaps he will be given a name when he meets his own fate...)
Borges was remarkably precise with language and so any and all ambiguity must be intended. The condition of "what is the author saying?" is the result the author was certainly looking for, by presenting a story that is also an enigma. (The "The Aleph", for instance, is presented as in the mystery genre, but the mystery carries the much more profound, religious context.)
To Borges, existence was a series of wonderful enigmas.
(I'm certain Borges wrote about this, but it's been so long, I couldn't tell you where specifically to look, only that it's in there somewhere, and that reading anything Borges wrote about writing is profoundly rewarding;)
The enigmatic quality of Borges' stories relates partly to textual hermeneutics from the inverse, game theory perspective of a narrative designer. the idea that so long as a text cannot be definitively analyzed, it will continue to hold interest.
(This is similar to the concept of a solved game, such a Tic-tac-toe, which loses appeal once the player has determined the solution. By contrast, AI may not beat humans at Chess and Go, but the games are computationally intractable and cannot be solved.)