Great pop songs are boiled-down emotion-a simple line or melody that says it all. And like an indie-pop version of "Call Me Maybe," Swiss-German duo BOY nails it with viral hit "Little Numbers": "Seven little numbers, baby, they could be a start. Seven little numbers, baby, I know yours by heart."

Simple, catchy, effective. And singer Valeska Steiner pulls it off in English--not her first language, but her fifth. Along with instrumentalist Sonja Glass, Steiner's already a hit in Europe, with BOY's debut album, "Mutual Friends," selling 100,000 in Germany alone, according to the Germany Music Industry Assn.

The record arrives stateside Feb. 26 on Nettwerk Music Group, just in time for the act's first run of U.S. shows the week following and the same day the single will be Starbucks' Pick of the Week. "Their lyrics will resonate with [American] audiences," Nettwerk VP of international A&R and publishing Mark Jowett says. "They tell great stories, and they do it well in English." BOY drafted Phoenix drummer Thomas Hedlund for four tracks; Mutual Friends has the same spark of that French phenom, cast through a Feist-on-uppers piano-pop filter. But it's the Barcelona-filmed "Little Numbers" video that's breaking through, with more than 7 million YouTube hits. "For German and Swiss bands, it's a much bigger step to get out of your country, and we did that last year," Steiner says. "But going to the States, well, that's even bigger."