For a decade or so, a major threat to your laptop wasn’t a virus, malware, or hacking — it was Janet Jackson’s hit song, “Rhythm Nation.”
What you might think of as an apocryphal urban legend was apparently true, including to some internal sleuthing by Microsoft employee and blogger Raymond Chen, who has unearthed some new details on one of tech’s more fascinating stories.
Let’s start at the beginning. In 2022, prolific storyteller Chen related a story that was told to him from a colleague who had previously worked on the Windows XP team. There was a problem: somehow, playing back “Rhythm Nation” over a laptop’s speakers would crash the laptop. In fact, it could crash nearby laptops as well. Microsoft tried to isolate the fault, eliminating other variables, and the staff were left with a single conclusion: it was the sound itself that was at fault.
Remember, laptops at the time didn’t ship with the SSDs that they do today. Instead, they used hard drives: 5,400-RPM hard drives with an actuator, magnetic heads, and platters. And it just so happened that “Rhythm Nation” inadvertently hit the resonant frequencies of at least one of the components. The vibration caused faults in the drive. It wasn’t enough to wobble the hard drive’s magnetic head into the platter — though that would do it! — but simply cause enough read faults that the laptop’s OS crashed.
Remember, resonant (or resonance) frequencies are just simple physics. Tap a glass, and it will “ring.” Project the same sound back at the glass, and it will vibrate in sympathy — even shatter. San Francisco’s Exploratorium museum once had a ton or so of metal suspended from a chain, and visitors could try to move the suspended metal using a tiny, cheap, bar magnet on a string. If you pulled slightly at the right time, the metal would eventually move. It’s the same principle that brought the Tacoma Narrows bridge down: small movements at the right frequency combine with one another.
For some reason, that’s exactly what happened with “Rhythm Nation.” Retired Microsoft engineer Dave Plummer (who worked with Chen) dug into it, too, concluding that something in the song also had hit the published resonance frequency of the Western Digital’s hard-drive platters. But Plummer was unable to reproduce the issue, prompting Chen to conclude that Plummer used the wrong hard drive — he used an external 5,400-RPM hard drive, and not one designed for laptops.
The important consequence of this, however, is that Microsoft specifically engineered in a fix: a specific filter (a notch filter, as Plummer notes) to eliminate or at least downplay the tiny frequency band. For years, if you listened to “Rhythm Nation” on your laptop, you’d hear the song minus that tiny little laptop-killing audio slice.
The update to this story was Chen’s question: how long did that notch filter remain in place?
Essentially, it remained from Windows XP (2001) until Windows 7 (2009), because Chen reported that another PC vendor still remained freaked out by Janet’s ability to crash laptops. Microsoft had tried to put in a rule that would make it possible to disable with all “Audio Processing Objects (APOs),” which included the notch filter.
“The vendor applied for an exception to this rule on the grounds that disabling their APO could result in physical damage to the computer,” Chen wrote. “If it were possible to disable their APO, word would get out that “You can get heavier bass if you go through these steps,” and of course you want more bass, right? I mean, who doesn’t want more bass? So people would uncheck the box and enjoy richer bass for a while, and then at some point in the future, the computer would crash mysteriously or (worse) produce incorrect results.”
The waiver meant that even if all of the APOs were disabled, the notch filter would remain in place. It was granted.
Of course, virtually all laptops today use SSDs, which don’t include mechanical components that can be affected by vibration. That’s not to say that the materials of an SSD don’t have their own resonance frequencies — they do, but there’s no indication that hitting them would even be possible with an audible tone, or that it could cause errors to occur.
That’s kind of a shame. Imagine how different the world would be if “Baby Shark” had caused laptops to fail. “Sorry, kiddo — guess we’ll have to listen to Daddy’s music instead.”