It would be incorrect to think the Milk Carton Kids' ever-growing fan base and success will sway them musically.

Yes, everyone says that and then goes off into the commercial land of vanilla sound. But this duo, known individually as Kenneth Pattengale and Joey Ryan, has already taken minor stances that foreshadow their ongoing track. Consider the plans for a recent television appearance on a high-profile talk show.

"It is almost as though people giving opportunities see your potential but have to mold it or help you mold it," said Ryan. "That even goes to little things such as what we wear onstage. We went on [the late night television show on TBS] "Conan" a few nights ago and there were murmurings about what we were going to wear. We said 'We are going to wear the suits we always wear. That is how we look. And this is how we play.' "

The pure folk/Americana sound of the Milk Carton Kids has been a constant since Pattengale and Ryan were solo performers in Los Angeles when they joined together. They began touring in 2011 after performing at SXSW. They released a live album, "Retrospect," that same year.

The Milk Carton Kids
» Where: Birchmere, 3701 Mount Vernon Ave., Alexandria
» When: 7:30 p.m. Tuesday
» Info: $20; 703-549-7500;

Critics quickly gave the duo rave reviews for their inventive guitar lines and intricate, interwoven vocals. Ryan noted that other kudos, including likening the duo to the Smothers' Brothers, left the two scratching their heads a bit.

"I take it the Smother's Brothers comparison is a fond one, but I've never seen a minute of the Smothers' Brothers," said Ryan of the much-loved folk duo who gained great popularity not just for their music but deadpan humor. "It is just a particular hole in my knowledge of American culture. ... I just don't know why everything we say everyone thinks is funny! We don't do that intentionally."

The good news, of course, is that praise for the duo's music is also widespread. So much so, in fact, that it has left the two in a bit of disbelief.

"It feels a little bit odd to accept compliments and congratulations because we're really just starting," said Ryan. "It's the start of something, so we don't feel a sense of arrival. The road ahead is really long and daunting, but it's a welcome road and we finally clearly see our path. I mean, this is our first album that was ever really in stores!"