While plenty of industry honors, roles in film and television, and appearances on late-night shows have all come Shelby Lynne’s way over her two-plus decades’ career, she’s never forgotten the fundamentals of her craft.

“With acting, I pretty much just use my singing credentials,” said the 43-year-old contemporary country singer-songwriter, who plays The Blue Door on Thursday. “I’m totally into that if something comes up that feels right.”

Something did come up when, back in 2005, Lynne appeared on the big screen as Carrie Cash, mother of Johnny, in the Oscar-winning biopic “Walk the Line,” starring Joaquin Phoenix as the Man in Black. She’s also had a few similar, smaller roles on TV, and while she finds it good fun, she said it hasn’t done too much for her presence as a musical performer.

“I try to keep [acting and music] separate,” she said. “Most everything I write comes out as a poem first. Sometimes they’ll turn into a song, and I don’t think acting has too much to do with that.”

That poetry flows from “Revelation Road,” the Grammy winner’s most recent and personal record, in which she focuses on details so specifically, they evoke a clear scene around the listener.

“I’m trying to write a story and paint a picture at the same time, is how I look at it,” she said, nodding to great Oklahoma songwriters Jimmy Webb and Woody Guthrie, the latter of whom she didn’t discover until her late 20s.

“Jimmy’s one of the greatest. We all look up to Jimmy, and I keep him really close to my heart and pen,” she said. “In my last 10, 12 years of my life, I’ve tried to educate myself on Woody. When you’re a kid, you look for that melody, but now I certainly appreciate his folk symbolism, and I probably wouldn’t have got that as a kid.”

Despite being around long enough to remember recording on cassette tapes, Lynne keeps her songwriting from turning pessimistic by staying wide-eyed. “I feel like now I’ve just gotten better, gotten the hang of it,” she said. “I’d not be here, lasting if I’d just slipped in and slid through and was lazy about it. I take it very serious. I want to do something great, so I keep that in the front. It’s my guiding light.”