Swedish sisterly duo First Aid Kit are wise well beyond their years. Comprised of Johanna Soderberg, who is in her early 20s, and her little sib Klara, still in her teens, they earned rave reviews back in 2010 for their debut album, 'The Big Black and the Blue,' then embarked on a lengthy world tour that tightened them up as a live act. By the time their sophomore album, 'The Lion's Roar,' dropped in January of this year, First Aid Kit were hands down one of the most popular musical exports coming out of Sweden.

As they've already issued three singles from 'Lion's Roar,' the sisters Soderberg already seem primed and ready to move on. Case in point would be the arrival of 'Wolf,' a non-album track which points to the future sound of the Kit: While past releases have mostly focused on a stripped-down, folky approach, 'Wolf' adds tribal drums and lush backing synths to the equation. As usual, the Soderbergs themselves keep their focus on the lyrics and their vocal delivery, and the result is one of the most fleshed-out tracks from the band yet.

We're not sure what producer was attached to this latest offering from First Aid Kit, but we love the direction they are headed and hope they work with him/her more often. For a band already so mature at such a young age, it seems like the sky is the limit.

Listen to First Aid Kit, 'Wolf'