Jordan Roseman, a.k.a. DJ Earworm, posted his first mash-up of Billboard’s Top 25 songs on YouTube in 2007, in what was at the time a one-off experiment to see how many songs he could fit together in one track. Five years later, his annual “United State of Pop” mix is a year-end viral staple, with millions of viewers checking in to see the year in pop music reflected through his dense, hyperactive musical lens. Each mix becomes its own song, a barometer of the national mood, and a pop-culture time capsule as narrated by the likes of Katy Perry, Taylor Swift, and Bruno Mars.

This weekend Earworm premiered his 2012 mash-up, “Shine Brighter” (embed at bottom). I spoke to him on the phone from his studio in San Francisco in mid-November, when he was still hard at work bringing it all together.

I’ve described the United States of Pop to others as a musical equivalent of reading a really good essay about pop music that year. You kind of get a feel for what ideas and themes were the strongest, you get a cut of everything that was the biggest and had the most lasting impression. Were you a big pop-music aficionado before you started making the mash-ups? Or was it more of a personal experiment than something inspired by a particular love for the songs?

I never love all the songs. But I’m fascinated by pop music, and I’m fascinated by how it relates to culture, and how the little nuances of development in the pop-music landscape reflect often significant cultural developments. I mean, at first it was just an experiment, and then I realized that it could be something more. The first year [my attitude] was like, “Can this be done?” and even the second year I was like, “Well, I might do it again, we’ll see if I can get it to work.” But by the third year I thought, well, not only do I have to do it, but I realized what it could be. At that point I thought maybe we could be, from the ground up, telling a story that reflects our collective experience, but that also reflects the spirit of the new year, in a way — the passage of time, and renewal, and this idea of us all going through it together. That’s when 2009 happened.

That one has gotten the most views, right?

Oh, yeah. By far.

Even listening to that now, hearing the pieces of all those songs brings back that year in such crystal-clear form. Is that your favorite one you’ve done?

I think it’s the one that stands the test of time, and it really was pure in terms of its spirit and in terms of its message. I think I was able to convey a message, but it was also a balance between trying to let people relive the songs that they liked, and trying to make a message that both has integrity and also isn’t overly introspective or overly cheesy.

What other themes have you found while making the mash-ups over the years? Like last year, for instance — what were some of the commonalities that you saw?

Oh, well, last year there was definitely [a sense of] great loss, and sort of resentment of that loss. And there’s also this other subtext of like, apocalypse, and the idea of “living for now,” which has been a really common theme in the last four or five years of pop music. I attached some of the political events that had gone on during the year, like Occupy, and so it sort of came together — there’s a great loss, and there’s great resentment, but we’re going to blow it all up and sort of have this nihilistic joy of the here and the now and “keep dancing while the world is going boom.” So it was kind of tying all those themes together. I also just loved how that Katy Perry hook sounded. A lot of it is just a musical thing.

This year I’m going even further musically. I feel like every year I learn a lesson from what I did right and what I did wrong, and I think last year there was almost too much emphasis on the words, not letting the hooks sing enough.

Do you find that a year in which you liked more of the music lends itself to an easier mash-up?

Yeah. I think, for instance — and I won’t count 2007 because I really didn’t have the hang of it yet — but the 2010 mash-up resonates the least for me, and that music also resonates the least for me. You know, it was the year that Ke$ha and [Taio Cruz’s] “Dynamite” came out, and all that. I was trying to convey a message about persistence and “keeping it going,” but it wasn’t as deep of a message, and I don’t know — I don’t know what happened. [Laughs.]

It’s funny, because in recent years, EDM has obviously gotten huge, and we’ve got a lot of songs at the top of the charts that seem like they would be more friendly for what you do. But in a way, I feel like when there was more song-based stuff like in ’09, you have more of a colorful cast of characters that are telling the story of the year through pop. Now you have these big hooks, but there’s less differentiation between songs.

There is a stylistic bottleneck that we might just be coming out of, in terms of the sameness in ’10 and ’11, and dance music just taking over. To me, this year, it’s about melody. It’s about the rebirth of melody. Even though that’s been starting to happen, it’s in full effect now. And also you see the success of fun., and to a lesser extent Mumford & Sons. It might be the dawn of a new thing that can take us back away from the 130 bpm dance music. I don’t know, it’s too early to tell. It’s sort of a continuation of [the popularity of] One Republic and Coldplay, in some ways, but it’s also taking a lot from the folk resurgence of more underground music.

When I think of this year, trying to imagine how I would reflect on it as far as all the music that’s coming out, you definitely have Mumford & Sons and a lot more traditional “band”-bands that have gotten really big —

And acoustic! Acoustic rock. It’s got a very gentle edge to it. It’s not like the indie thing of the early 2000s.

Yeah, nothing like the new garage bands. But then you also have these huge, inescapable songs like “Gangnam Style” and “Call Me Maybe.” So I’m assuming you’re going to have those in there at some point.

Oh yeah, it’s necessary. [Laughs.]

How are you going to mix together those different sides?

I’m not exactly sure. I might have both energies of music represented — and then there’s also this thing of, like — well, we’ll see how successful it is, but I’ve got a lot of dubstep [to work with], like in Justin Bieber’s song “As Long As You Love Me.” Which is also very 2012. And you know, 20 years in the future, you’re gonna hear that 140 beats a minute and that “waa waa waa waa” and you’re gonna go, “Oh my god, I remember 2012!”

What are some of the themes you see emerging as you work on this year’s mix?

There’s a lot of uncertainty, and not knowing. And this feeling of — not loss so much as being lost. And then there’s also a lot of revelation and realization as well. I want to focus on that, this sort of transformation, and hopefully introduce some form of deliverance at the end. But [it’s mostly about] this idea of not knowing, realizing, and transforming. And I see those themes in “Somebody That I Used to Know” — this idea of something changing, or [Katy Perry’s] “Wide Awake.” Or even [Maroon 5’s] “Payphone” — “All these fairy tales are full of it.” This realization that something you thought was true isn’t. [Quoting fun.’s “Some Nights”:] “What do I stand for? What do I stand for? Some nights I don’t know anymore.”

You mentioned you wanted to try to have some sense of change this year — what songs embody that for you?

Well, I — hang on, I have notes here [laughs]. I cut and paste all the lyrics into four categories. [Pause.] Oh, like Katy Perry saying “I’m letting go tonight.” And Gotye saying “You said that you could let it go,” and The Wanted: “My universe will never be the same.” And Kanye: “Let me get in my zone, let me get in my zone.” Who says “Show you another side of me, a side you never thought you would see”? [Pause.] Oh, that’s from [Flo Rida’s] “Wild Ones.” And then you have Kelly Clarkson saying “You think you’ve got the best of me, you think you’ve got the last laugh, you don’t know me ’cause you’re dead wrong.” And Justin Bieber says “We both know it’s a cruel world, but I’ll take my chances.”

So I don’t know exactly — [laughs] — there’s probably a lot of lyrics I haven’t zeroed in on yet, but I was just sort of taking those lyrics and putting them into bins to try to get this thesis going.

A lot of people would hear those lyrics and say “Pop music is so vague, how do you pull any meaning out of these songs”?

None are ever empty. They all represent a person’s point of view about a situation. And so you have to ask yourself, well, what are these points of view? Are there similarities? Are there differences? And also, what is it about them that has some sort of resonance, that goes beyond, that connects and makes you feel a little more than it would have originally?

In the end, even songs that are essentially built by committee are still trying to find a way to connect with people and become hugely popular.

These songs aren’t hugely popular for no reason. There’s a musical aspect, but every single one of these songs has lyrics that are resonating with people. And it’s not always the entire lyric that resonates, it could just be a fragment. Like I think of Pitbull, “Give me everything tonight.” Well, he’s actually making a sexual proposition. But you don’t feel that when you’re singing along with it. If you take the words by themselves, you’re just asking the world for everything, you know?

Totally. There are just these very basic, elemental feelings that seem to wax and wane in pop.

Yeah. And even if you’re just talking about hooking up for a night, it’s the way you’re talking about it. There are all these extra aspects reflecting a larger truth.

Are there any recurring elements just purely musically?

Well, yeah, the return of the melody. Even thinking about last year, like “Moves Like Jagger,” that crazy “do do do do do do” which was sort of out of the ordinary [at the time], but now is sort of the norm. Most of these songs this year have some serious contours; I’m thinking particularly of “We Are Young,” which just has these crazy melodic contours. Even [Nicki Minaj’s] “Starships” — [sings] “Are meant to flyyyyy” — you know, it’s a very specific passage, not a melisma. It’s a specific multi-note syllable.

And it’s so refreshing, because with a lot of Katy Perry songs, for example, if you start listening to them back-to-back, her choruses are usually built off one note. And then because those were the songs that were big, everyone was kind of mimicking that, in a way.

[Quoting J.Lo] “On the floor!”

Totally! Well, I’m looking forward to hearing something more upbeat and melodic in the mash-up this year. Because there have definitely been a couple of angsty years.

I know, it’s hard. Already it feels a bit dark, so I’m trying to figure it out — because you look at the words and you think, Oh god! And there’s also Flo Rida — he might have three songs [in the Top 25], and I’m just — I just feel like his whole style, even though it’s been very popular this year, it sounds like what’s been going on and not what’s about to go on.

What song from this year do you think is indicative of what’s about to go on?

Well, the number-one song this year is going to be “Somebody That I Used to Know,” which is definitely indicative of where we’re going. Definitely the two fun. songs, and also if it makes it [into the Top 25], “Too Close” by Alex Clare, and Bruno Mars’s “Locked Out of Heaven.” Those are definitely pop songs that are like, OK, now I see that this [kind of music] could be really big next year.

Well, I’m looking forward to the mix, and I’ll let you get back to work on it — by the way, what songs are you working with today?

I’ve been messing around with using “As Long As You Love Me” as a base. But it might not end up in the mash-up, in the [Top 25]. I’ve been messing with that, and trying to get some compelling combinations of songs. Not even one particular song, but trying to get some good messages that are both musically compelling and that flow lyrically and that are going to at least try not to keep you in the darkness. There is a lot of darkness in these songs, but I don’t want “The United State of Pop” to be a downer, at least not this year. So I want to find a way to get out of the darkness while still keeping the integrity. But it’s the same thing as real life, trying to find lightness in the dark — the lightness has to be real; you can’t just make it up, you know?