Sonja picked her out the moment she opened her mouth. Her soft, but powerful, croon stood out amid a field of tested musicians.

That was the simple, right-place, right-time meeting of bassist Sonja Glass and vocalist Valeska Steiner, who would quickly form the duo Boy.

“We complete each other somehow, musically,” Glass said. “She was so special to me.”

Maybe that’s part of why their debut album is called “Mutual Friends.” Out since 2011 in Germany, “Mutual Friends” only showed up in the United States at the beginning of 2013. But Glass insists it hasn’t become tedious because the two have been able to spread the word to so many places and audiences, making every “album debut” and tour feel different.

Forget notions of raging German techno beats or serious metal. The women of Boy put forth a light, bouncy variety of seemingly American indie pop — see their single “Little Numbers.” Steiner’s lyrics are exclusively in English, and it isn’t ‘til Glass opens her mouth, emitting a heavy German accent, that their background becomes evident.  

“Valeska was already singing in English when I met her,” Glass said. “Her language is Swiss-German, and no one understands that — we don’t like the sound of her voice when she sings in German.”

They say they’re normal, uninteresting people off the stage. But Glass’ sly asides and affable personality, mixed with the eclectic emotional range of their music, suggest otherwise.

She alludes to long periods with Steiner spent forging the friendship that comes across in their music — the tough childhood spent with three siblings and a single mother in Hamburg, Germany, and the long slog of multiple bands before meeting Steiner.  

On the surface, they may seem like just another pleasant addition to the indie scene, but there’s something going on behind the scenes with Boy — subtle and touching clues about their close relationship that make them different from your average indie act.

There’s Glass, who’ll laugh off the fact that a female duo is called Boy but won’t go any further. It’s like they enjoy the facade of being two women with a nice disc, all while subversively laughing at some inside joke about pop sensibilities that no one in the audience cares about because the tunes are so fun.

There are songs like “Oh Boy,” which sounds almost sarcastic with its over-the-top descriptions of an alluring female. But it’s not all layered meaning — there are plenty of endearing, Paul Simon-esque moments of lament and melancholy.

Then there are more upfront songs like “Skin,” an ode to the inescapability of superficiality. Steiner’s chorus: “You can feel like part of something if you’re part of the scene / You can make your life feel pretty add a little ice and gin.”

Lyrics like this are drizzled over the album like chocolate icing on an unexceptional, but delicious, vanilla cake — certainly enough to bring you back for seconds.

What: Boy

When: 7 p.m., Tuesday

Where: First Avenue Mainroom, 701 N. First Ave., Minneapolis

Cost: $18

Age: 18+