Onstage, Robyn whips her platinum coif around as though she's trying to escape a headlock. She punches the air. She kicks at phantoms. And when her bittersweet pop hit "Dancing on My Own" reaches its conclusion, she throws her arms out as if shoving the song off a cliff.

A few tunes later, she wolfs down a banana and chucks the peel into the audience. Of all her wild gestures, this one feels the most illicit.

That's because we're in the concert hall of Berns Salonger, an opulent 19th-century ballroom adorned with three hulking chandeliers and a whole lot of history. Swedish writer August Strindberg immortalized this place in his 1879 novel, "The Red Room," and 130-odd years later, its breathtaking architecture is filled with dancing Swedes, blinking strobes and a pop star at the height of her fame.

In the United States, you might be arrested for throwing garbage around in a room this magnificent.

But this is Stockholm, a global beehive of 21st-century pop, where Swedes treat their music with the reverence it deserves. In recent years, Scandinavia's largest country has churned out some of the most finely crafted, detail-oriented pop on the planet, produced by artists such as Stockholm sensations Lykke Li and the Knife and Gothenburg outsiders the Tough Alliance and jj. When I visit the land responsible for all these fantastic sounds, it makes perfect sense. In Stockholm, the nightclubs are clean and intimate, the sound systems are loud and lush, the DJs are encyclopedic, and the bands can be brilliant.

This Robyn show is practically a national event. her second homecoming gig in an intimate two-night stand. The only concertgoers at Berns who aren't clapping along to the 31-year-old singer's candy-coated disco are older women sipping white wine and too-cool teenagers who look as if they'd stumbled out of A Perfect Guide, the Swedish fashion magazine I leaf through the next morning.

A few titles down the newsstand rack, Robyn's smirk adorns the cover of Fokus, the Swedish equivalent of Time. She has been declared "Swede of the Year."

"It makes me proud to be Swedish," the clerk says, ringing up my purchase. "She's more famous than Abba."

Members of the Radio Dept., an indie-pop trio living here in Stockholm, think that Robyn is "just okay."

We're sitting at the front table of Nada, one of numerous incredibly cozy bars that dot the island of Sodermalm - or Soder - the trendy, arts-friendly district that houses most of the city's musical night life. We order a round of Falcon lager, Sweden's cheap, drinkable answer to PBR, and talk about the national popscape while a DJ in a Metallica T-shirt spins Joni Mitchell and Marvin Gaye.

The band is prepping for a big U.S. tour, which includes a stop at Washington's Rock & Roll Hotel on Feb. 1. Like its new album, their English is superb - and the same goes for just about everyone I meet during my four nights exploring Stockholm's bars and nightclubs.

And while the weather outside is frightful, frontman Johan Duncanson assures me that I've chosen a fine season to visit. Sure, the Scandinavian summers promise 20-plus hours of sunshiny good times, but most Swedish artists spend them on the road, festival-hopping in lower Europe. If you want to see Swedish bands in their natural habitat, now is the time.

But what about that sunshine? Indie bands from America's Pacific Northwest are thought to be hyper-prolific because the rain keeps them indoors, writing songs. Do the dark winters have anything to do with the music that comes pouring out of Sweden? Keyboardist Daniel Tjaeder laughs and says the band hardly rehearses. But it did take three years to record its new album. So maybe.

We pay our tab and shuffle over to Indigo, another Sodermalm bar where neon lights glow and garage rock blares. The crunch of guitars is momentarily interrupted by a saccharine '80s Christmas carol called "Tand Ett Ljus" ("Light a Candle") by the Swedish pop group Triad.

"I think they are playing this ironically," says Johann.

I hope not. Like almost every new song I hear in Stockholm, this one sounds amazing.

On the Radio Dept.'s advice, I take the T-Bana subway out to the western edge of Sodermalm to visit Strand, a newer nightclub nestled on the waterfront. Outside, the silence is lunar, but behind the club's glass frontage is a warm, clean, spacious bar filled with impossibly gorgeous young people and the greatest music you've never heard.

Young women - presumably all shampoo commercial models - play air drums to the selections by Joel Lindberg, tonight's DJ. He dishes up tunes by the Beach Boys, Dolly Parton and the Doors that I never even knew existed. Is this some kind of parallel pop universe? Or maybe heaven?

Turns out, the Swedes are very diligent students when it comes to music from the U.S. and the U.K. To hear them DJ is to have everything you know about pop thrown back at you in high-def - not unlike staring into one of those concave makeup mirrors where every pore on your face becomes dimple-size.

"We're very sensitive to trends," says Emelie Thoren, a music critic and DJ spinning classic soul records at Riche 24 hours later. "As Swedes, we don't want to be in the background."

Located across the water in the bustling Stureplan neighborhood, Riche is one of many music-centric downtown bars catering to a more upscale clientele. I'm here to chat with Karin Strom, a journalist and singer who says that Sweden's postmillennial pop explosion felt tangible. "In the '90s it was all British and American music," she says. "Then suddenly, we had our own."

She's referring to the international rise of aughties rock outfits the Hives, the Sahara Hotnights and - whoa! Two members of the Sahara Hotnights just walked by, searching for a seat. Then Karin's boyfriend bumps into a pal he recently worked with on the set of a Peter, Bjorn and John video. Everyone seems connected to music, and nobody's surprised to see each other. "In New York or Paris, you don't run into people at bars," Karin says. "It's not like that here."

The next day, Lykke Li's eyes follow me around Soder. The enchanting young singer lives in this neighborhood, but I'm talking about her concert posters, which hang at almost every bus stop.

I'm up early to meet Lars Jamtelid, the guy behind the blog Look Notes, a great resource for anyone curious about Sweden's pop vanguard.

"It all started right here," Lars says, but quickly catches himself. "It sounds like we're filming a documentary!" We're tromping through the slush on Skanegatan, a street that once served as the locus of the Stockholm indie scene, thanks to the decades-old record store Pet Sounds. Since then, Pet Sounds has soldiered on - despite the incredible popularity of the Swedish music-streaming Web site Spotify - and has opened a sister bar and restaurant across the street.

The record store carries heaps of Swedish pop, indie, psych-rock and jazz on vinyl and CD, but over lunch Lars is quick to rattle off a litany of great new bands that aren't on the shelves: Sail a Whale, Korallreven, Museum of Bellas Artes, Bandjo, the Embassy . . . .

That night, I hit the streets to try to approximate the bounty of the Swedish pop blogosphere, bouncing from venue to venue, gig to gig.

My first stop is the Sodra Teatern, another spectacular 19th-century theater that hosts readings, plays, comedians and, surprisingly, a ton of rock concerts. Built in 1859, the main theater boasts frescoed ceilings and 414 weathered red velvet seats. The curtain goes up and out strides Britta Persson, a Stockholm singer whose music lives at the intersection of the Pretenders and the Cure.

Her set is delightful, but I have to split early if I want to catch California band Best Coast at Debaser Slussen, the city's most storied rock club. Near the entry, a gaggle of monks in blue robes has gathered, smoking cigarettes in the freezing chill. As I get closer, I realize they're just showgoers swaddled in complimentary Snuggieish blankets provided by the club.

Smoking isn't allowed indoors, but Debaser Slussen still smells a little dank, making it stand out among the mostly pristine nightclubs here. But the young crowd is still exceedingly polite, watching Best Coast's blustery set as if taking in a college lecture.

Debaser Slussen's sister club, Debaser Medis, has a show tonight, too. If I hustle, I'll catch the tail end of Swedish rock mainstays the Soundtrack of Our Lives. Situated in a large community center that also houses a gym and a public pool, Debaser Medis is one of the larger live music venues in the city. As the band's psychedelic rock wafts through the air, so does the faint smell of chlorine.

And like so many great rock-and-roll evenings, it ends at a kebab stand, noshing on cheap falafel, surrounded by sloshy strangers. A very drunk man in a very sharp suit - his English completely intelligible despite a mouthful of gyro - asks why I chose to visit Stockholm at this frigid time of year.

I tell him that I came to hear Swedish pop music.

"Ah!" he lights up. "So you came to see Robyn!"

Yep. Does he think she's bigger than Abba?

"Oh, definitely."