What is The "Black Foliage"?

Olivia Tremor Control's "Black Foliage: Animation Music, Volume 1" is rife with references to its namesake. There are several instrumental tracks titled "Black Foliage (Animation X)", X being the current portion of the sequence, a number from one to five. Mid-way through the record is "Black Foliage (Itself)", the only non-instrumental of the namesake tracks. An excerpt from that song:

You are the subject of sketches
I made for a sculpture in sound.
When you pass the black foliage
Imagine an eternity wrapped in silver sound

When you pass the black extension
Imagine a ceremony
Just below the lids of your eyes

The Black Foliage is itself the black extension, because it is shadowy memories, extending from the world to speak to us. This shadow of a space is where history quietly lies dormant. Black Foliage is history itself, finding its expression in the spaces we occupy. Such an imprint is referenced in a number of other places, most importantly in "California Demise 3":

Home of the saints, burn down the walls
Between spaces, between friends
Archaic angels pose in rows
And in my garden angels grow

They come inside only at night
Inter-static sunbeams
Are the angels' only storybook

Friends!

They don't bother wearing seatbelts
To protect them from the wreck
They've already died in the California demise

The "California Demise" isn't just a single event that happened at a distinct point in time, it's an ongoing debacle and its victims can't enjoy the Foliage. They "come inside only at night", when the shadows are no longer casting the storybook of darkness, and they cannot write to a storybook they can't see.

Of course, there's no example of such a storybook we'll immediately find better than the record in question. There are literal sonic collages of memories and imprints, including samples of fans discussing dreams they've had. The number of people who touched the record is staggering, all being just a big group of friends out to create for the joy of it.

Most importantly, the artists want nothing less than to grant the listener their own agency in enjoying the Black Foliage. Everything above is nobody's truth except mine, and whatever you feel and see while among the Black Foliage is your truth. Nothing weighs more heavily than a shadow, though. We can't isolate ourselves from that extension of our world.