Listen to Sarah Lee Guthrie and Johnny Irion’s new CD, Exploration, for any number of reasons, if not just to hear the word lieu used in a song. For the average folkie, this collection of twelve distinctly American songs satisfies not just the curiosity about the latest Guthrie who’s hunkered down with a guitar, a pen, and some paper, but also a more general lust for more, still more, twangy songs. Guthrie — daughter, of course, to Arlo, and granddaughter to Woody — grew up perhaps too sensitive to the mantle of legendhood hovering nearby, and didn’t touch music until she was eighteen. “I knew that as soon as I picked up a guitar it was all over,” said Guthrie in a radio interview last month. “My first show would be a couple hundred people there — which was what happened. But I wasn’t ready for that till I was eighteen.” In California she met South Carolina singer-songwriter Irion (“EYE-ree-un”). He encouraged her music, they sang together, they fell in love, they got married. Today, seven years later, they’re playing 180 dates a year, all over the country. They were in London last month. Each has released a solo album, and Exploration is their first CD as a couple; Irion penned most of the songs, including the opener, “In Lieu of Flowers” — a sad and simple country song.

Standing in front of the florist for hours

I’ve come up with this for you in lieu of flowers.

The cowritten “Cease Fire,” sort of a train song and sort of not, rocks out nicely, and showcases a mischievous break in Guthrie’s wispy voice. At the center of the album is a previously unrecorded Pete Seeger song about Martin Luther King, and Irion’s scathing protest song from which the disk takes its name.

The production on Exploration sometimes overpowers what could have been a sparer, but more personal, more riveting record. Too often, unnecessary drum fills and swelling organs clutter up the space around the songs and dilute the pleasure of hearing Guthrie and Irion’s eerily matched voices in close harmony. But Guthrie’s own “Mornin’s Over” doesn’t play this card. It’s a tiny little two-minute song, mysterious and plaintive and just right. The final cut, “Gotta Prove,” busts out; it finds its banjo-fueled groove and rides it over the mountains.

Sarah Lee Guthrie and Johnny Irion are at the Ark on Monday, April 18.