A bright and groove-heavy take on alt-pop, the music of Capital Cities draws its infectious energy from the endless juxtapositions within each song: genre-bending production meets indelible melody, high-concept artistry meets classic pop sensibility, clever lyricism meets raw emotion. The L.A.-based duo first unveiled that aesthetic with their breakout hit “Safe and Sound,” a 2011 release that went multi-platinum around the world and shot to the top 10 on the Billboard Hot 100. With their new single “Vowels,” singer/songwriter/multi-instrumentalists Ryan Merchant and Sebu Simonian push their inventive musicality even further to dream up a sound that’s instantly magnetic.

Built on silken grooves, warped effects, and glossy guitar tones, “Vowels” delivers wordless sing-song harmonies that put a brilliant twist on the deep frustration at the heart of the lyrics. “When you can’t express yourself with words, sometimes you just want to scream to get it all out,” says Simonian. “You need vowels to do that!”

With its melancholy undertones and shimmering feel, “Vowels” reveals a complex emotionality shaped in part by Capital Cities’ equal passion for the breezy joy of the Bee Gees and moody introspection of Jeff Buckley. The band also explored that intersection of hope and darkness on “Safe and Sound,” a song conceived as “an antidote to the human tendency to think in apocalyptic terms and not really look at the logic of the world around us,” according to Merchant.

First appearing on the band’s independently released self-titled EP in 2011 and later featured on their 2013 debut album In a Tidal Wave of Mystery, “Safe and Sound” ultimately proved irresistible as the track reached no. 1 on alternative radio and no. 2 on Billboard’s Mainstream Top 40 chart. Meanwhile, its video—a glorious celebration of dance crazes from across the eras—earned a Grammy Award nomination for Best Music Video and won the Best Visual Effects prize at the MTV Video Music Awards.

For all its undeniable appeal, “Safe and Sound” came to life before Merchant and Simonian even had any intention of forming a band together. The two first crossed paths when Merchant—then seeking a producer for a solo project—responded to a Craigslist ad posted by Simonian. After meeting up at Simonian’s studio, they felt an immediate bond that had much to do with their shared tastes and near-lifelong immersion in music.

Born in Syria to Armenian parents and raised in Southern California, Simonian began playing piano at the age of three and later sang in school choirs and formed a rock band in his mid-teens. He studied music in college and eventually turned down an opera scholarship to pursue a career in pop music. Merchant, on the other hand, grew up in San Francisco and got his start playing piano when he was 10. “From an early age I wasn’t really interested in becoming a proficient player—I just had this impulse to mess around on the piano, to play chords and make up lyrics and melodies,” says Merchant, who picked up guitar at age 12 and drums in high school.

Once they teamed up, Merchant and Simonian began collaborating on each other’s solo projects and soon formed a music company that quickly saw them working on major commercials, including one that required a cover of David Bowie’s “Space Oddity,” which was approved by Bowie himself. “In the meantime we were writing all these cool songs together, and that included an early incarnation of ‘Safe and Sound,’” Merchant recalls. “People kept telling us, ‘You need to do something with that song,’ so after a while we decided to start performing it live as a band, and everything kind of took off from there.”

Initially an underground hit that scored massive blog attention, “Safe and Sound” prompted the duo to launch a self-financed radio campaign and head out on a self-booked tour throughout Europe and South America. By the end of 2012, with their fanbase rapidly expanding across the globe, Capital Cities had inked a deal with Capitol Records and set to work on their full-length debut.

In working on “Vowels” and new material, Capital Cities stripped down their creative approach by honing in on a selection of songs and focusing on refining each arrangement. “We spent a month just sitting down at the piano and hammering out the songs, and not even touching a computer or thinking about production,” says Merchant. “We try to write what feels cool and what feels good to sing—it’s this very intuitive thing, where if something pops out or has an interesting spark, you’ve got to see where it goes.” Adds Simonian: “It’s all about the words and melody.”

Now gearing up for a string of live dates, Capital Cities have recently added a jazz vibraphone player and classical guitarist to the lineup for their notoriously dazzling live show. Whether performing live or crafting new material for their second full-length effort (set for 2017), the duo aims to create an emotionally charged experience that’s transportive for themselves and for the listener. “When you either listen to or perform music, it’s a meditation” says Simonian. “It affects you on so many different levels and allows you to experience all these different emotions. It’s therapeutic.” And when it comes to making music, that process can sometimes take on a transcendent quality that Merchant describes as addictive. “When you’re writing and you have a moment where something magical happens, it’s like a drug,” he says. “You stumble upon something that feels so good and just validates what you’re doing, and it gives everything this bigger sense of purpose. I want to just keep that going and constantly create good music.”