The Sep. 21, 1981 issue of The New Yorker has a cartoon in which a man is thrown out of a bar, followed by his Rubik's Cube. An advertisement touts the virtues of Pioneer's LaserDisc player. ("As for the picture quality, well, just look at the picture of Liza [Minnelli] below.") And the Talk of the Town section offers an explainer on a suddenly ubiquitous new device.

The Walkman is a hand-sized high-fidelity tape player or radio connected by wires to a pair of high-quality foam-rubber headphones the size of half-dollars.

Never again would there be a moment when half-dollars were more familiar, as a reference point, than personal headphones. The New Yorker piece is one of several contemporary accounts quoted by Rebecca Tuhus-Dubrow in her 2017 book Personal Stereo.

The 142-page paperback is about the size of a Walkman, but that's more or less a coincidence: it's part of a Bloomsbury series called "Object Lessons," with volumes exploring "the hidden lives of ordinary things" like eggs, socks, and tumors. To fit her compact scope, Tuhus-Dubrow divides her history into three easy sections: "Novelty," "Norm," and "Nostalgia."

Personal Stereo accomplishes a lot in the short time it takes to read. It reminds readers (or informs them) of just how revolutionary the Walkman experience was, and how much it anticipated today's conversations about technology and personal space.

When the device hit the U.S. market in December 1979, it offered a revolutionary fusion of private and public. Walking down the street listening to, say, Supertramp, you were at once listening to a mass product (Breakfast in America) and having an intensely individualized experience in a public space. The feeling was so revolutionary, Sony built their advertising campaign around what people said about the Walkman: there was really no way to understand it until you slipped those foam half-dollars over your ears and tried it for yourself.

Tuhus-Dubrow begins her "Novelty" section with a capsule history of Sony, a corporation that more or less literally rose from the ashes of postwar Japan. By the mid-1970s, co-founders Masaru Ibuka and Akio Morita had already achieved global success with various audiovisual products. Stories vary on exactly how the Walkman was conceived, but there's general agreement that it was Ibuka's idea to combine various innovations into an unprecedented product.

Within the company, the Walkman didn't seem particularly revolutionary. From an engineer's standpoint, it didn't represent a technical breakthrough. Its genius wasn't in what it added, but in what it subtracted: a Walkman didn't have a record function, and it didn't have speakers. All you could do was listen, through stereo headphones. The idea of such a private portable listening experience was so counterintuitive, the first model had two headphone jacks so you could share your music with a friend.

Once the Walkman hit stores, though, everyone had to have one — despite the fact that its retail price of $200 was the equivalent of about $600 today. The seeds of today's podcast landscape were planted as users grabbed the portable stereos and played whatever tapes they pleased: pop music, classical music, language learning tapes. Audiobook sales boomed, and the New York Times reported that "something astonishing is happening to the record business: it is becoming the cassette business as well."

Concerns about home taping proliferated as consumers grabbed up blank tapes to record their LPs for Walkman replay, but in the end, the Walkman proved a boom to the recording industry. In the mid-1980s, cassettes enjoyed a heyday as the dominant music format, as vinyl sales slid and the compact disc era dawned. As Tuhus-Dubrow notes, portable CD players became more popular but never really approached the ubiquity of cassette Walkmans: they weren't as portable, and the skipping problem that made them impractical for exercising was never satisfactorily resolved.

It was, of course, the iPod that ultimately eclipsed the Walkman. Sony, Tuhus-Dubrow argues, saw the MP3 revolution coming but couldn't bring a similarly pioneering product to market because they'd entered the content end of the music industry when they became a record label themselves, and feared the impact of digital music piracy — a development that, in fairness to Sony, did end up devastating the industry as home taping never had.

That's all covered in the "Nostalgia" section, which also touches on the analog redux movement (primarily a vinyl boom, though cassette mixtapes have their ardent partisans) and the ways in which smartphones serve as today's personal stereos. Really, though, the book's best section is its "Norm" core: Tuhus-Dubrow's concise exploration of the world Walkmans made.

She points out that personal stereos were among the signature products of the splashy and materialistic '80s: the must-have means for consuming some of the greatest pop music ever made. They were initially seen as the yuppie (read: white and wealthy) answer to the boom boxes that sent sounds echoing through the canyons of Queens, but before long, even hip-hop heads were nodding silently with their featherweight headphones.

Inevitably, there were debates about hearing damage and dangerous distraction: real concerns, even if somewhat overblown. In 1982, the town of Woodbridge, New Jersey banned pedestrians from crossing the street while wearing headphones, with a penalty of up to five days in jail. A man named Oscar Gross responded with a pointed act of civil disobedience: he donned a pair of headphones that weren't even plugged in, and stepped into the street. Police duly issued a citation, to Gross's delight.

The personal stereo was seen as yet another device by which teens could shut out their elders and withdraw from everything good and holy in the world. "When teen-agers have reached the point where they feel they must shut out the sounds of the Ohio State Fair," read a stunningly non-ironic op-ed from 1981, "society is surely ready to collapse."

Users often described the Walkman experience as cinematic, for reasons that Tuhus-Dubrow articulately explains. "That medium [cinema] was the first to introduce the notion of 'non-diegetic sound': sound imposed on the story from without. Some felt like they were in the movie, others like they were watching it." People described the Walkman experience as colorful, or likened it to drugs. The iconic iPod advertisements of the 2000s were essentially a way of visualizing how people had always described the experience of listening to music on portable headphones.

As Tuhus-Dubrow notes, one of the paradigmatic depictions of a Walkman in the movies is the opening of 1985's Back to the Future. Marty McFly throws his earphones on and flies off on his skateboard. We hear Huey Lewis singing about "The Power of Love": playing over the credits, that music would be considered non-diegetic in an earlier film, but with the Walkman, the scene is just putting us in Marty's head. We're sharing his experience, the music shutting out everything else.