Joan Shelley

At Red Room at Café 939, June 15 at 8 p.m. Tickets: $14. 617-747-2261, www.cafe939.com

When Joan Shelley is asked about a review of her recent release, “Over and Even,’’ that spoke of her “predilection for eccentricity,’’ she’s a little surprised at first. Compared to her music-making friends, she avers, she’s the sanest of the bunch. But then she considers further. She says she likes the characterization, “because it gives freedom. To stay between the lines these days is horribly suffocating. I think you have to be eccentric to have a voice that matters at all, so I take that as a compliment.’’

Shelley is out on tour in duo mode with the fine guitarist Nathan Salsburg in the wake of that outside-the-lines record. We spoke with the singer-songwriter by phone the day after a show in Portland, Ore.; she’ll make her way east for a date here in June, featuring Salsburg and, she hints, perhaps a “mystery guest.’’

The Kentuckian’s third solo record, “Over and Even’’ creates a sense of being both strikingly out of step and timeless. One hears echoes reminiscent of American old-time, British folk, or ’70s Laurel Canyon, but the music has a beautiful sparseness and resonating stillness wholly its own. Her singing is a marvel: crystalline, reserved, at times almost matter-of fact, held back in a way that underlines its power. Her lyrics, allusive and elusive, evoke the poetic.

Many of the record’s songs seem to reflect an experiencing of the natural world, almost at the point of physical contact: splitting wood, rolling in pine needles, falling leaves, the sound and smell of rain. Human experiences and interactions seem to be intertwined with that world, or even to be experienced through its lens. “If you go,’’ says a lover in “Stay on My Shore,’’ “the wind will blow you back to me / And if your boat is broken out on the rocks / It wasn’t anger, but a longing.’’

The most powerful songs, Shelley notes, take a listener into deeper focus; one experiences something in little vignettes, and can then pan out into bigger pictures. “That’s the only way I know how to connect through songs,’’ she says. “I like writing story-songs, too, and creating characters. But that’s how it becomes vivid to me: to make it a sensory experience, to try to make the listener feel something I was feeling.’’

Ambiguity allows listeners to have their own experience with the songs, Shelley proposes, and meaning can be mysterious to her as well. When someone asks her what a particular song is about, “I usually say where I was when I wrote it, and what the circumstances were, where the images came from — and then I don’t really like to say if it had a meaning. Sometimes it did, I think, and then a year goes by, and it’s like, oh, that’s what that was about. Looking back, that voice that showed up that day had a different perspective, maybe a longer view of the thing that was going on, than the one I could have articulated if I told you that day.

“It’s really weird to me,’’ she says, laughing.

Musically, “Over and Even’’ is informed by a principle of being as bare-bones as possible, of playing “what we needed, and only what we needed, to convey the songs and carry a little bit of that spirit.’’ That aesthetic is in part a reaction to the sonic world around her.

“It may have to do with something in my nature,’’ she surmises. “Anytime somebody insists that the way to do it is a certain way — and in my ear, the radio says you have to have a drummer all the time, and a bassist, and a keyboardist — the world is saying, this is how you make a band! This is what music is! So my nature is to say, maybe you don’t, and maybe the drummer hits the cymbal three times, and then he sits down. It’s this kind of pushing back, to make it just as clear or just as powerful, but not how you thought it would be. That’s the hope.’’

Stuart Munro can be reached at sj.munro@verizon.net.