For any non-nerds who might (for some reason) read this, the far lands were an accidental feature of early versions of minecraft. The game generates terrain up to 8 times the equivalent size of earth, but if you somehow wandered even father than that, you would reach a point where the generation process no longer works normally. Characteristics of the normal game's biomes are still present, but twisted into visually striking, impossible new forms. Even basic game physics is warped: some objects can appear 2D, you need to travel by horse to avoid falling out of the world through the ground, etc. For me and probably many others, the far lands have a sort of romantic (in an almost Burkean sense) appeal.
The Basics
So how does the analogy work? Basically, I think that some music is to "normal" music what the far lands are to "normal" minecraft. Terrain in minecraft proper consists of various biomes, which can be seen as analogous to musical genres or idioms. The specifics may vary, but you know generally what to expect and look for in a jungle biome or a jungle track. That's not to imply that strictly idiomatic music can't be surprising or even mind-blowing--it's just that it's "mindblowingness" comes from expected elements being executed really well, e.g. a pop song with a really catchy vocal melody, or an ambient work with really lush sounds. It's the kind of shit you can achieve purely through a combination of youtube tutorial-level knowledge and practice-induced luck. (And I don't mean that dismissively.) Anyways, terrain / music governed by the expectations of biome / genre is the "normal" side of things; it's what the far lands are not.
Is far lands music, then, just any music that's innovative or experimental? Not exactly--it would be a pretty boring concept if it were that simple. When people use those terms, they're often referring to music that they think either a) combines elements from previously separate music idioms together or b) creates an entirely new music idiom. This would be equivalent to minecraft mods that a) create an additional biome that combines elements from various existing biomes or b) create an entirely new biome. Neither one quite captures the nature of the far lands, though.
Sandy on Earth (this is probably the most brow-furrowing-ly abstract part, pls don't stop here!)
Now I'm left with the difficult part: explaining what the hell is so special about the far lands themselves, and how it applies to music / art. First of all, I should clarify that this analogy isn't meant to be taken too literally. Really serious nerds may know that the far lands form according to some predictable patterns of behavior. But for the purposes of this post, they are simply, to quote my namesake, "a place where reality slips and slides, expands and contracts". Their defining characteristic is that they distort and push past the limits of existing categories / sets of expectations rather than form new ones. The cases described in the previous paragraph are different because they don't really break free of biome / genre expectations in the same way, but simply rearrange or replace those expectations. (Again, I'm not trying to be dismissive here; these approaches to innovation can of course be very exciting too.) But at the same time, the far lands aren't entirely disconnected from normality. After all, you can't bend reality if there's no "reality" established in the first place. Some sort of referentiality is needed. Without the context of the normal game, the minecraft far lands wouldn't carry the same resonance when you finally come across them. And without existing music idioms, the same would be true for far lands music. But I still haven't really explained what all this actually looks (sounds) like in music, which was, after all, supposed to be the point of writing this post. To do that, I'll need to introduce two further subconcepts in the analogy...
Sorcery
Again, far lands music doesn't readjust your expectations so much it just continually subverts them. When this is done really well, I think it can give the music a sort of "impossible" quality: you can't believe what you're hearing, or maybe listening to it feels akin to being in a dream. It's obviously difficult to point out specific musical characteristics that far lands music tends to have without reducing it to a formula (and therefore defeating the entire concept). But very broadly speaking, far lands music tends to subvert a particular idiom's standard composition structures by making them in some sense more complex or fragmentary (possibly both), by honing in on unique characteristics of a genre and pushing them farther than its constraints would allow, and sometimes throwing elements from other genres into the maelstrom as well. But music that simply combines disparate elements without much changing / distorting them doesn't have the same effect, because you can easily tell what's going on once you recognize the idioms its drawing on. So in a sense, such music still has limits--while far lands music, despite its referential nature, does not. It's more difficult to distinguish far lands music from music that creates its own idiom--but as we'll see below, doing so may be a matter of perspective.
Relative vs. Absolute Far Lands
All this talk of "expectations" leads pretty naturally to the conclusion that what is or isn't far lands music depends on the reference points of particular listeners. If you're familiar with one music idiom but not another, music from the latter might be far lands music to you. For example, a lot of academic electronic music seems this way to me because I'm more versed in / used to popular music. So a work like Jean-Claude Risset's Sud seems to take elements you'd hear in ambient / chillout music (flowing water sounds, birdsong, drones, etc.) and do amazing, mind bending things with them (transform one sound into another, merge ambient sounds with harmonic sounds, etc.) But if I were more familiar with that sort of computer music, I might be more able to classify and predict Risset's apparent sorcery. Usually, I think it's easiest to say that x music is far lands music in relation to x idiom (as in the example above).
But still, I can't shake the feeling that there is absolute far lands music out there, which would still strain credulity even if the listener was familiar with all music ever recorded, or even ever made. However, if it does exist, it's likely stuff that only people like this guy know about.
Examples
-Risset, Parmegiani, Stockhausen et al. (again, in relation to most ambient, psychedelic, "soundscape" type music)
-Autechre (in relation to hip hop / dance music--maybe even an example of absolute far lands music?)
-Vektroid (in relation to new-age, videogame soundtracks, etc.; this whole post was partly inspired by listening to Shader again recently, which is far lands music even in relation to vaporwave itself)
-Trout Mask Replica (in relation to blues / rock)
-Twin Infinitives (in relation to rock)
-surreal house (in relation to Chicago house; described in my first post)
-edit: Maryanne Amacher is probably an absolute example
-edit2: I also forgot that Autechre actually use a very similar analogy to describe their music in this interview, which I think kind of helps validate this concept:
Sean Booth: It's like gaming sometimes, trying to guide it. There's some very basic AI in there—I mean only using "if" statements, conditionals, if-the-situation-is-this-then-do-that type things. It's as basic as a game AI, if you look at the AI for the characters in a game, it's just a chain of "if" statements, basically. It's very much on a level to that, really. So playing music on it is about as fun as playing Grand Theft Auto, doing random shit with pedestrians, seeing if you can get someone to run up a wall or whatever. If I can get the musical equivalent of that, I'm generally quite happy.
Rob Brown: Make the cars float. Transparent cars that float. That's what we aim for.
Misc Notes
It's probably obvious from reading this that I tend to really like music that I think fits with this analogy. It's not like I think it's automatically better than everything else--but I do suspend that it tends to stand the test of time better than most "normal" music. This is because, ideally, it should be capable of surprising you no matter how much normal music idioms are combined or multiply in number, since it exists outside them. Also, I've stressed the strangeness of far lands music, but I also think of it as the most intuitive (rather than consciously "logically" formulated) way of approaching music. In a sense, it's the most personal art around.