‘Is it like a tape recorder? Can we rewind it just once more?’

In 1968, Robert Zajonc released Attitudinal Effects of Mere Exposure, a study showing that the repetition of an object (be it a written character, a word or a sound) can make it more pleasant to the person observing it. Scientists and others have expanded on that idea over the years, including discoveries around the subconscious “learning” that we do the more often we hear a song or an album.

There’s an experiment that helps lay this idea out: A listener is played the same song repeatedly, and each time indicates via a slider when they feel the music getting tense (usually around a song’s high point). At the beginning, they register the tension after the climatic high point. As the listens pile up, though, that slide becomes earlier and earlier, as they subconsciously learn the song’s ins and outs.

“They're really configuring the way they're orienting so that they're kind of thinking through and experiencing what's about to happen,” says Elizabeth Hellmuth Margulis, the principle investigator of the Music Cognition Lab at the University of Arkansas. She literally wrote the book on the effects of repetition in music, entitled On Repeat: How Music Plays the Mind. “That's just a kind of involvement that's different than just reacting to sounds that are happening out there.” That anticipation then leads to a positive response when the brain “predicts” the song’s movements successfully.

“Once a listener ‘knows how it goes,’” Margulis writes in On Repeat, “he is free to sing along, or indulge in some air guitar or tap out the rhythms. … [R]epetitions affect even the highest-level impressions of music—responses like enjoyment and interest—suggesting that their work is largely done implicitly, outside conscious awareness.”

Zachary Wallmark, the director of the MuSci Lab at Southern Methodist University, recently conducted a neuro-imaging study where participants brought in their favorite or least-favorite songs and had brain scans taken while listening to both these familiar songs and other, unfamiliar ones.

“We found a pretty huge effect of familiarity on a pretty wide swath of the brain,” he says of the study, “Including reward areas, so the areas that light up during eating fatty food and sex.”

It makes sense that the first album one encounters of a band will, over time, accumulate the most repeat listens. It has the chance to rack up plays before the listener explores the rest of the catalog.

“A large number of psychological tests have shown that we experience our most intense emotional responses from familiar music,” writes scientist and musician John Powell in Why You Love Music.

‘You want to be the song, the song that you hear in your head.’

Pop is, in many ways, the last experimental U2 album (in as much as borrowing the sounds of Berlin could be considered “experimental”). It’s miles apart from the band’s ’80s, earnest, Irishmen-in-America phase, and dives deeper into electronic soundscapes than the preceding pair of albums, Achtung Baby and Zooropa. Therefore, if one’s first exposure to U2 is Pop, then the first idea of the band can be formed by a dancefloor-adjacent song like “Discotheque,” creating a platonic ideal of what the band is supposed to sound like.

“Our schema for a Lawrence Welk concert includes accordions, but not distorted electric guitars,” writes Daniel Levitin in This is Your Brain on Music, “and our schema for a Metallica concert is the opposite.”

That idea of a schema, used here as a set of ways of classifying a certain band, genre or even song, can be important to the way we react to new material. Our brains expect a certain sound, and while some deviation is fine, go too far and expectations aren’t fulfilled.

“You have this sort of representation, this kind of scaffolding about how a thing goes, what the features are, and what it involves,” Margulis said. “If you're encountering music that's in a really, really unfamiliar style and you have trouble forming predictions and engaging with it in terms of expectations, that tends to be a challenging experience for most people.”

“Trying to find that balance between familiarity and surprise is really the magic of pop music,” says Joel Beckerman, author of The Sonic Boom: How Sound Transforms the Way We Think, Feel, and Buy. “I think that when that balance, that delicate balance, gets messed up for people, it's no longer familiar then, and they have a certain expectation about the experience they're going to have.”

Of course, if my first real experience with U2’s music was Pop, it would mean that my brain was establishing a schema, a platonic ideal, for what a “U2 album” sounded like: a collaboration among The Edge’s guitar, Bono’s voice and the dirty electronica of co-producers Howie B. and Flood. More importantly, that ideal wouldn’t conflict with a previously stored framework.

“I would argue that not only do we like the first album most because of the familiarity, we also somewhat paradoxically like it because it's the most novel,” Wallmark says. “By that, what I mean is that musical liking often follows what we can think of as kind of a Goldilocks principle. It needs to be this just right balance of familiarity and novelty.”

‘Then you find that feeling just won’t go away.’

My first listen to Pop came on my Discman while taking a bus back to school from a midnight on-sale party at Tower Records (that sentence is so age-defining that I could put it on my driver’s license instead of a date and no bouncer would think twice). I had two copies: One for me and one for my first college crush.

“You're not even talking about the music so much at that point,” says Wellmark. “You're talking about this intermingling of a specific artist, a specific album, and your contingencies at that moment. You were uniquely susceptible to being imprinted upon at that time, maybe more so than you are right now.”

That “imprinting” is most powerful during the “plasticity period.” It’s the point in life where we’re most open to being influenced, to having our tastes altered. Many people’s musical tastes don’t change much from age 25 on for exactly that reason: they know what they like, and all that they don’t like.

Studies have shown that we hold onto the music of our youth. “Part of the reason we remember songs from our teenage years is because those years were times of self-discovery,” Levitin writes, “And as a consequence, they were emotionally charged; in general, we tend to remember thing that have an emotional component.”

It’s that combination of sense memory and repetition that creates nostalgia, which is a powerful motivator on its own. This may be especially true for reminiscing about listening to an album for the first time. In a Psychology Today article, Ira Hyman, currently a professor at Western Washington University, maintains that nostalgia “may prove most profound when there are few encounters with the sensation between that long-ago period and the present.” And there’s only one “first time” with a record.

“When you talk about really liking the first time you heard something, maybe you saw it at a concert live and now you're listening to this recorded version, it's like the experience you're having of this recorded version kind of carries with it your experience at the concert,” says Margulis. “So, there's some kind of autobiographical memory or some kind of meaning that's interwoven into the experience that didn't exist until it had kind of become a part of your life”

“One of the reasons you love that album, might not just be that it's the first thing you heard, or first time you heard the band and you like the band,” says Beckerman. “It might have also been who you were with, or what you were doing or the time of your life.”

‘Don’t try too hard to think, don’t think at all.'

Repetition, frameworks and nostalgia can give the first exposure to an album an advantage in terms of picking a favorite. It can make an album more pleasurable to listen to, create an ideal version of the band against which future versions of the record will be compared, and wrap all of that around a happy memory. It’s made U2’s latter-day, adult-contemporary albums a tough listen for me, while making the early (and, from a critic’s eye, superior) output pleasing, but without the emotional connection that creates passion.

So is my love of Pop defensible? Sure. But with so many variables that help control how our brains create pleasure via music, defensible on its own merits may not be the point.