Twenty years after jolting the 1990s with OK Computer, a dystopia-themed album alternating between cryptic melancholy and demented distortion, Radiohead celebrated the seminal album’s anniversary by releasing an artful album package that includes a curious tape cassette. In addition to long-buried demos and studio experimentation, the cassette also contains a secret message, encoded using an obsolete computer language.

The final four minutes of audio are filled with high-pitched computer tones that, to most listeners, sound like nothing more than artistic bleeps. Some keen-witted fans, however, discovered that the tones comprised a code and found a way to decrypt the message.

Doing so requires processing the audio tones into visual data by using a 1982 ZX Spectrum home computer, which was designed to accept data written onto cassette tapes — just like we stick thumb drives into our computers today. But those that don’t have an archaic 35-year-old ZX Spectrum handy can instead download a program that mimics ZX Spectrum’s software, an aptly named ZX Spectrum emulator and feed it the digital version of the 78-minute tape that came with the anniversary box set.

The 1982 ZX Spectrum home computer.

Reddit user Sidblunt was one of the first to detail the decryption process online and provided the Radiohead program file for other fans to download. Another Reddit user got the emulator program to play Radiohead’s digitized tape code, and, using Youtube, made the secret message not so secret, as you can see below.

Altogether, the ZX Spectrum (or its emulator) spits out some 30 lines of code, which contain some simple text snippets. In the first segment of the message, the band reveals that it is now “inside your home computer,” and what follows next are some four minutes of beeping as the screen is populated with line after line of words, symbols, and letters. Herein, perhaps, lies a code within a code.

Elsewhere in the code is the message: “congratulations….you’ve found the secret message syd lives hmmmm. We should get out more.” It’s been suggested that “syd” here refers to Syd Barrett, the Pink Floyd frontman and songwriter who was ousted for being too experimental.

Radiohead, however, has not shied away from experimentation and, after 32 years as a band, can still be counted upon to defy convention and use technology in quirky, inventive ways. In 2014, for example, the band released the app Polyfauna, which had users exploring a cryptic world of unsettling landscapes and shape-shifting trees and creatures, all while trying to catch an elusive red ball. In 2016, the band defied technology outright, temporarily deleting itself from the internet, but soon returned.

After the release of OK Computer came Kid A, where the band at times completely shunned traditional rock instrumentation, relying on the beeping tones and textures created by the very machines OK Computer warned us all about, four years earlier.

Photos via Wikimedia Commons