An introduction to Nordic tracks Under Byen

While the US music market scrambles to keep up with the latest wave of hyped Scandinavian rock bands, the Museum of Fine Arts offers a primer of sorts on Friday with a bill that includes Swedish kindred spirits El Perro del Mar and Frida Hyvonen and headlining Danish post-rockers Under Byen. Here's a beginner's guide to all three.

"Unfair to say," wrote David Byrne on his blog back in October, "but a bit like Sigur Rós, but with words, songs, and more aggressive and fractured rhythms. . . . Come to think of it, there might be a little Arcade Fire in there as well."

Byrne was giving such high praise to Under Byen, a band few people outside of Denmark have heard and whose name even fewer people can pronounce correctly. (It's "Oh'nah-Boon," by the way, and it means "Under the City.")

Under Byen is the dark horse on the MFA bill. Unlike El Perro del Mar and Frida Hyvonen, Under Byen does not make pop music that begs for a tambourine. The octet grinds out its dense post-rock with a mix of cello, violin, saw, bass, guitar, drums, and synthesizers. (That Arcade Fire comparison suddenly makes sense.)

In various incarnations, the band has been around since 1995, toiling under the radar while attracting boldfaced fans such as Byrne and David Fricke, the Rolling Stone writer who deemed Under Byen "the best band in Denmark, probably the best band in the world," back in 2003.

There are challenges to us mere mortals, of course, starting with lyrics sung only in Danish. If you don't speak the language, it's easy to get caught up in references to Bjork and even the Cocteau Twins.

"Samme Stof Som Stof" ("Same Fabric as Fabric"), the band's new album on the Canadian label Paper Bag Records, packs emotional heft, with brooding instrumentation pitted against Henriette Sennenvaldt's reverbed vocals. Within three songs the band can go from PJ Harvey-style jagged rockers ("Pilot") to ambient lullabies ("Tindrer").

The band describes the album as "different, haunting, and unmistakably Under Byen." That's in English, and we still don't know what it means.

Violinist Nils Grondahl explains: "I think by ' unmistakably Under Byen' we mean music or an album where nothing is sacred and nothing is being taken too seriously, despite the fact that we sometimes sound 'very pathos like.' "

The name of Sarah Assbring's one-woman band came to her almost like a mirage. Deep in thought on a beach on a Spanish island, she was contemplating the music she had always wanted to make yet hadn't. Suddenly, she spotted a dog on the beach; for some reason, it felt like an epiphany, and that scrappy dog became her muse.

Hence El Perro del Mar, which literally means "the sea dog" in Spanish. The whimsical name suits this Swedish singer-songwriter with a pixie haircut and a beguiling voice that, at times, suggests Kate Bush reimagined as a long-lost Shangri-La.

Modern pop songs rarely get any more moonstruck than "God Knows (You Gotta Give to Get)," from El Perro del Mar's self-titled debut, which was released on Memphis Industries late last year in the United States. With its Brill Building orchestrations and girl-group harmonies, the song's chorus, constructed almost like a 12-bar blues, is pure cotton candy: "You gotta give to get/ You gotta give to get back/ to the love."

It's not all sunshine and lollipops, though. There's real melancholy lurking beneath the glossy veneers. "Party" isn't the kind of bash you'd probably like to attend, unless you fancy a night of sulking with the Smiths playing in the background. And "Candy" is a rainy-day confession that the song's protagonist is going out to buy some candy on a Saturday night. Her doleful tone implies she probably won't get any, yet the shimmering accompaniment is hopeful, even jubilant.

Assbring revels in this duality in her songs: "I like that people don't know if they should feel happy or sad when they hear my music," she says.

As confident as the songs on "El Perro del Mar" sound, Assbring admits she guards them closely, allowing only her boyfriend to hear them before they're done.

"For me, a song is very vulnerable in the beginning," she says.

Halfway into Frida Hyvonen's song "You Never Got Me Right," most people profess to one of two feelings: sheer exhilaration or the onset of a headache. Both reactions are warranted.

A violent showcase of pummeled piano and hair-splitting tempo shifts, "You Never Got Me Right" is the showstopper and black sheep on Hyvonen's new album, "Until Death Comes," on Secretly Canadian. It's a doozy, too, with Hyvonen's wailing voice mixed coarsely to pierce the competing instruments. Clocking in just shy of two minutes, it's probably the nastiest and shortest breakup song ever put to record, succinctly turning her insecurities into an indictment of her scorned lover: "And then you intellectualized my emotions/ And called me baby, baby, baby, baby in the wrong way!"

The song sounds the way Hyvonen appears on the album cover: dangerous and maybe just a little bit manic. The rest of the album, though, isn't quite as agitated. It's surprisingly confessional; on "Once I Was a Serene Teenage Child," she relays her memories of youthful sexual exploration (with frank lyrics we can't print), and on "Djuna!," she's sentimental: "Someday when I'm not broke/ I'll kiss my boys goodbye/ Their embroidered handkerchiefs waving me off."

"In the beginning of my career as a performer, it would be therapeutic just to be onstage," Hyvonen says. "But nowadays I think I am probably the therapist."

If El Perro del Mar is the aloof wallflower who sits demurely in the corner, Hyvonen is her brazen sister who's been forged in the fires of fellow piano pounder Laura Nyro, eager to get everything off her chest. And if that gives you a headache or thrills you, then so be it.