Tift Merritt is a singer-songwriter of fine shadings, a stylist who plays hopscotch with pigeonholes.

The North Carolina native has released five albums in the past eight years, each seeming to lean toward one of the closely connected subgenres that comprise her approach: Americana, blue-eyed soul, alt-country, pure folk, folk-rock.

Dusty Springfield, Linda Ronstadt, Emmylou Harris and Lucinda Williams are all credible points of comparison -- except Merritt has a deeper catalogue of original compositions than the first three, and she sings better than Williams.

She's always had a literary bent.

"When I started out, playing gigs and making records was much newer to me than writing," she said by phone from a tour that brings her to the Fine Line Sunday. "When I look back on my first record, I see an inordinate amount of 5 1/2-minute songs. They were short stories. Now I am a songwriter." She laughed. "Three minutes."

Because she prefers her songwriting process to be more intuitive than purposeful, she only belatedly realized the dozen tunes on her latest, "See You on the Moon," could be organized around "beginnings and endings." Potential sources of inspiration are easy to spot -- Merritt recently married the man who has been the drummer in her band for 12 years, and there were other marriages and a pregnancy among members of her road and recording crew as "See You on the Moon" was being conceived.

Yet the romantic bookends of infatuation and heartbreak occupy only a portion of the subject matter. Yes, there is a terse kiss-off song, the soulfully scornful "Papercut." But the lyrics that linger are found on the title track, which bids adieu to a childhood friend, and "Feel the World," which seems cast as one grandparent welcoming the other into the afterlife.

Along with her inability to settle on a predictable style, one reason Merritt hasn't enjoyed more commercial success is this tendency to go gentle with her powerhouse voice.

"There is always a negotiation between words and music," Merritt said. "As much as I like to sing loud and hard, what I like best is singing as one person saying something to another person. That's the heart of it. I'm not a showman -- I'm not 'American Idol.' I don't think I could get up onstage unless the writing of the song led the way for me."

That sentiment guides the set list for Sunday's show and other stops on the current tour. "Some songs you outgrow and other material you rediscover and address in a different way. I like to play the songs where we don't feel like we have gotten to the bottom of that lake yet. ... As a writer you hope the songs can stand on their own; that when you come back to them, they've still got at least one leg you can use."