Remember ephemera? I mean, you’re not supposed to — it’s short-term material meant to leave a vague informational imprint on your mind before receding to make room for more important things. But that kind of detritus is in short supply lately: The internet’s tendency to preserve every last piece of tossed-off thought, whether it’s a simple observation on the hour’s news or a half-assed joke that gets you a little like-share-and-subscribe traction, is filed away somewhere for easy accessibility so it can be used for data-mining, targeted marketing, and down-the-road receipts to throw around during time-wasting arguments. We’re not there yet, but we’re awfully close to having our culture shaped by an entire cohort of grown adults who can access an entire lifetime’s worth of memory triggers at will and spend as much time as they want vividly resuscitating experiences that, for previous generations, used to be half-remembered, then misremembered, then forgotten completely.

Nostalgia, however, hasn’t quite caught up. Twenty years ago, recollections of strange or fascinating things from childhood had to be more or less left vague — occasionally sought out in libraries or video rentals if it seemed important enough, but otherwise just loosely reduced to “this was a thing that existed — pretty wild, huh?”

An entire genre of music — hip-hop, the pivotal genre of its time (and ours, still) — had sustained itself for well over a decade at that point by recognizing that those fragmented memories, evoked in chopped-up and retrofitted form through sampling, could give those memories a simultaneous reckoning with both individualized personal experience and the extended musical lineage that predated it. What did James Brown mean to a 1969 radio listener, a 1979 Bronx DJ, a 1992 raver? That shape was always there to be changed, recognizable but modular and flexible, pieces of the past that didn’t have to sound like the past at all. Producers could give you the gist, but they’d need to patch in their own details to have something concrete to hold on to, and you could recognize their fingerprints where they’d been left in the rebuilding process.

But soon enough, once the internet made sample-spotting and access to obscure media and memetic consensus far easier, a monetized, aggregated, monocultural idea of shared memory became a sort of pop-culture default mode. It’s not just that Steven Spielberg just made nearly half a billion in international box office gross off “this was a thing that existed” — the music world fell into it, too, from vaporwave’s “what if ’80s R&B but slower” to the reduction of ’90s debris like Smash Mouth, 311, and Santana’s “Smooth” into talismans of their own recursive existence. It’s the unnerving endgame of geek culture as consumerism, wide-breadth-surface-depth bloat where recognition is mistaken for understanding. Pharrell Williams got the notion early this century that N*E*R*D made for a good backronym, he just got the wording wrong: he claimed No-one Ever Really Dies when the more accurate pronoun is Nothing. A dozen years later, he was singing with Daft Punk and Nile Rodgers, as three acts that had started out by steeping their music in era-defining newness had finally come together to invoke a very specific version of 1978. It was a nice place to visit, but who would want to live there?

OK, I went on a bit, but this is what it’s like to sink deep enough into the idea of Music Has The Right To Children turning 20 and subsequently getting its turn under the anniversary microscope. The first full-length album by Scottish siblings Michael and Marcus Eoin Sandison, dba Boards Of Canada, Music Has The Right To Children built off an accumulated few years’ worth of officially released recordings — and a far longer history of homemade cassette-splicing experiments — that made the name Boards Of Canada synonymous with pop-music hauntology. Jacques Derrida had conjured up the term hauntology just five years previous in his book Spectres Of Marx, using it to describe a sense of feeling detached from time, history, and language amidst ideas that refuse to acknowledge they’ve supposedly died. (Basically, ontology for ghosts — turns out not even leftist philosophers can resist cornball wordplay.) UK cultural critics picked up on this, and alongside the late Mark Fisher, Simon Reynolds invoked that term specifically to refer to music that evoked the past through the present in uncanny ways. Reynolds’ 2011 book Retromania: Pop Culture’s Addiction To Its Own Past pinpointed Boards Of Canada as music’s first real hauntologists: “BOC’s artificially faded and discoloured textures stir up the kinds of feelings you get from watching old home movies that are speckled with blotches of colour, or from leafing through a family photo album full of snapshots that are turning an autumnal yellow. It’s like you’re witnessing the fading of your own memories.”

Reynolds reiterated those points and expanded on them recently in a recent piece for Pitchfork, where he emphasized the specificity of a sort of shared moment in time that Boards Of Canada and their listeners latched onto. That time, of Gen X UK juvenile-into-adolescent mid-late ’70s life, centered around a sort of young-adult sci-fi-fueled ambivalence, where the pastoral and the technological clashed in ways that made the idea of utopian futurism feel more apprehensive than it might have been just a few years earlier. It was a time when documentaries and educational films about the natural world and the old ways of agrarian and indigenous culture were scored by the latest in analog synthesizers. This was when filmed dispatches through the lens of the North came in across the Atlantic, reflecting the fading British Empire in cultural parallels that seemed just off-centered enough to be mysterious. Boards Of Canada evoked that celluloid voyage into a bigger world from their name on down, as sure as the Rolling Stones and Black Sabbath branded themselves through all the implications that a Muddy Waters or Mario Bava namecheck could.

So how does Boards Of Canada’s music still resonate outside that particular space and time? After all, their sonic approximation of childhood mystery feels specifically analog: the sound of distortion and warping that comes from weathered film and copy-of-a-copy-of-a-copy cassette dubs, specific to particular media experiences of the ’70s and ’80s. Anything that worn-sounding, it seems, must have passed through many sets of hands and eyes and ears, creating a sort of collective subconscious that places certain signs of weathering and aging into tactile, audible reflections of the fallibility of memory, and the things we evoke to help sustain what we have left. Childhood and the nostalgia that it accumulates for later in life isn’t just about the action figures we can buy on eBay or the cartoons a couple clicks away on YouTube — it’s about the things we can’t access anymore. You grow up facing a world you know almost nothing about, one that’s far bigger than you could ever comprehend. And then it turns out that your own piece of that world, the one that sustained the identity you first learned to cultivate and use as the lens through which you learned things? That corner’s gone before you realize it, and there’s no way to recreate it. The neighborhood corner store is a Starbucks now; somebody else lives in a remodeled version of the house you came home to; that one friend you used to waste whole summers with has become faceless and nameless.

And this is how Boards Of Canada did what they could to find a route back: they sustained a sense of wonder, albeit not necessarily in that wide-eyed innocent sort of way most basic nostalgists operate in. It worked more in the sense that they made music which trigged a certain childhood experience of being shown something about how the world worked and not knowing what the hell was going on. Growing up in a certain era means sitting in front of the TV watching PBS or BBC Schools and having educational lessons set to billowing, burbling electronic music — something paid homage to in the absurdist Robert Popper/Peter Serafinowicz parody series Look Around You — and BoC played up their interest in a sort of natural-world subject matter in both contemporaneous interviews and the music itself. Tracks take on the sense of an edutainment/documentary gone imbalanced: Sesame Street appears frequently, from “The Color Of The Fire” manipulating the voiceover from an animation where a girl draws a Valentine to “Aquarius” turning a problem-solving “yeah, that’s right!” into a brush with synesthesia (“orange!“) and a counting exercise that wanders erratically into enigmatically coded random numbers. And that carries over into the song titles themselves — “Telephasic Workshop,” “Triangles & Rhombuses,” “Roygbiv,” and most memorably “Pete Standing Alone,” a nod to the protagonist of an NFB documentary who comes to terms with the conflict between his industrial-world upbringing and his indigenous heritage.

With their music as a sort of theater of the mind meant to evoke a loosely familiar but deliberately vague set of childhood experiences, Boards Of Canada have frequently been referred to by themselves and others as “psychedelia” — a tag maybe more appropriate than “IDM” for a group that’s professed a preference for Joni Mitchell and My Bloody Valentine over the latest dance music (though they’re obviously simpatico to peers like Aphex Twin and Autechre). Their style, centered primarily around melodic qualities despite their ability to craft a good head-nod beat, has aged a lot less noticeably than some of their glitchier, post-jungle contemporaries; you can hear the 1998 in Squarepusher or μ-Ziq albums of the era a lot more clearly than you can in Music Has The Right To Children. And the implied “D” in IDM has stirred up eyerolls in interviews. (“It bothered us that if you go into the big stores our stuff is always sitting in the dance music section,” Mike told Pitchfork. “We never made a dance record in our entire career but our stuff stilll gets thrown in there.”)

But this sense of exploration in their music, of letting the messiness and decay not only remain but add character to it, transcends the psychedelic stereotype of “music to take drugs by” to become music as a mind-altering substance. This approach was revealed in a March ’98 profile, said to be the band’s first published interview: “You could choose to listen to the melodies on the record and enjoy them purely as melodies, or you could read into the references a bit more and perhaps connect with that, or you could choose to come and see us live and see our thoughts abstracted out on video, and if it works the listener might go ‘Yeah this is familiar but I don’t know why’.” The music imprints ideas in your head, subliminally or through uncanny association: opener “Wildlife Analysis” sounds like an old TV ident left to wander into the woods, the treated, wobbly synth harmonies of “Olson” could’ve come from a half-remembered Stevie Wonder or Gary Wright song heard as background music during some family car ride, and “Turquoise Hexagon Sun” sinks its minimalist, graceful melody in so deep through repetition that the realization you can hear indistinct voices in the background is almost startling. There’s something deeper in the music than just music — why else would it add a free-speech/First Amendment message at the end of an album that’s almost entirely instrumental, with all the words in the vocal samples being allusive at best?

Of course, Boards Of Canada were working from their own memories of what they’d experienced musically, so going back to find something like the 1977 compilation Musiques De L’o.N.F. / Music Of The N.F.B., which includes the actual soundtracks of notable films like the anti-war stop-motion parable “Neighbours” or the early computer-graphics experiment “Metadata,” turns up compositions that don’t sound superficially similar in technique or melody but have that same unknowable sense of evocative mystery to them. And BoC’s successors, despite not having much to go on in their attempts to capture that same sense — the Sandisons famously kept their recording techniques and equipment tightly under wraps, part of their characteristic mystique — found their own angles to work. The aforementioned hauntology found its way into the roster of British label Ghost Box, whose groups like the Advisory Circle, the Focus Group, and Belbury Poly pick up a sort of rural-occult vibe off their vintage-electronic library music influences. Black Moth Super Rainbow took a similar mixture of bucolic psychedelia and primitive synthesizers and loosely Americanized it into a noisy fusion of ’60s acid folk, ’70s boogie-rock, and ’80s electro that added words just as vividly unsettling as the music. Flying Lotus joined Warp as a BOC labelmate and released Los Angeles 10 years after Music Has The Right To Children, expanding on its blueprint of textural organic-electronic music to make the beats as headswimming as the melodies. (He slyly sampled pre-MHtRtC classic “Everything You Do Is A Balloon” for last year’s “Post Requisite.”) And even soundtracks themselves folded back in on BOC as an influence, with Disasterpeace’s mournfully beautiful music for the film It Follows and games like Fez and Hyper Light Drifter picking up those same disoriented-discovery vibes in chiptune form.

And the irony of it all is that for the longest time, Boards Of Canada came across like they wanted to be a half-remembered entity in themselves: their live shows were rare, their interviews were sparse, and their discography went from sporadic to roughly once-a-decade. But the phases they went through, from the darker atmosphere of 2002’s Geogaddi to the guitar-laced The Campfire Headphase in 2005 to 2013’s subtle contemporary reckoning Tomorrow’s Harvest, were more shifts than leaps. And in keeping their style detached from anything easily recognizable trend-wise, they’ve also become detached enough from time that listening to them makes a collective nostalgia even more indistinct than it was 20 years ago. Sure, you can watch those National Film Board Of Canada shorts any time you want now. But if you bought Music Has The Right To Children soon enough after it came out, there’s an almost dead certainty that the place you bought it from no longer exists. And we wind up with new memories to watch fade.