Unless you’re prepared to be disillusioned, never meet your heroes. That’s the conventional wisdom, but maybe no one ever mentioned it to Klara and Johanna Söderberg. When Monsters of Folk—the supergroup that includes Bright Eyes members Conor Oberst and Mike Mogis—played the Söderbergs’ hometown of Stockholm, Sweden, in 2009, the sisters used their connections to get backstage. Reached at home via telephone, Klara remembers being too starstruck to say much of anything, but she did manage to hand Oberst some music by First Aid Kit, her duo with Johanna.

“I just completely blanked,” Klara admits. “He was the first musician that really inspired us to start writing songs, so he meant so much to us. And I’d thought about it before; you know, what I would say. But then standing there, it was sort of like it didn’t really matter what I said, because it would never fully describe how I felt.”

The music must have done the talking for her, because the Bright Eyes guys quickly became fans and friends of First Aid Kit. Collaborators, too: Mogis produced and played a variety of instruments on the duo’s most recent album, The Lion’s Roar. For his part, Oberst sang on the record’s rollicking final track, “King of the World”, which he also cowrote.

Like its predecessor, 2010’s The Big Black & the Blue, The Lion’s Roar is focused on the spun-gold close harmonies of the Söderbergs, but the second album (released in January) is a big, confident step forward sonically. Songs such as the dramatic title track and “I Found a Way” have lush arrangements that evoke the widescreen vista of a Mojave Desert sunset.

“For us, this record really felt like the natural next step,” Klara says. “It was never purposefully adding another instrument to it. It always felt like, ‘This needs to be here.’ So every instrument on the record really has a reason for being there. I really like the way this record sounds. It might be too early to say what’s going to happen with the next record, because we’ve only just started writing songs for it, but for us the most important thing is that the vocals will always be in the centre, no matter the instrumentation around it.”

Arguably, the finest moment on The Lion’s Roar is “Emmylou”, a heart-stopping beauty of a country weeper buoyed by Mogis’s shiver-inducing pedal-steel lines. The song is both a lament for a failed romance and a loving tribute to a few of First Aid Kit’s influences, namely singers Johnny Cash, June Carter Cash, Gram Parsons, and Emmylou Harris.

Of those four country-music giants, only Harris remains alive, and she’s still very active. She even sang on three of the tracks on the 2005 Bright Eyes album I’m Wide Awake, It’s Morning. Given that, you’d think the Söderbergs would be keen to work their connections yet again and arrange a meeting with her.

“I get nervous just thinking of that, or her even hearing the song,” Klara admits. “That would be crazy.”

If such a meeting did happen, what would the 19-year-old Swede say to the 64-year-old icon?

“I feel like I need to think about that for a while,” she says. “I could probably write an essay, or a book, to her. First off, I think I’d just say ‘Thank you.’ ”

First Aid Kit plays Venue on Tuesday (April 10).