“Band Aid” is a movie with an all-female crew, but it’s not especially ladylike.

The frequently funny, just as frequently bawdy “Band Aid” comes by its R rating honestly, and honesty is the movie’s policy — it’s a down-and-dirty picture of a marriage that’s faltering, even as both parties strive mightily (and goofily) to make things work.

Their plan sounds like something from a movie studio pitch meeting, but it happens to be drawn from life — when writer-director-star Zoe Lister-Jones (who hired women for nearly all of the behind-the-camera work) would squabble with her husband, she started to sing the bickering as a song, taking the edge off the argument and turning it into informal, amusing therapy.

That’s the set-up here — several years into a marriage marked by personal and career set-backs, Anna (Lister-Jones) and Ben (Adam Pally) are on each other’s last nerve. Dishes pile up in the sink, leading to an argument that renews itself every day.

The subject of the dishes is a substitute for a larger, deeper problem they don’t want to talk about, and Anna’s idea to sing rather than shout is another way to release the tension. They dig out their old instruments from high school (he’s on guitar, she’s on bass) and enlist their weirdo neighbor (Fred Armisen) as drummer, before working up the nerve to attend an open-mic night, a prelude to bigger things.

The songs (co-written by Kyle Forester) are funny and so is much of the dialogue, which is salty but resonantly tuned to the realities of marriage, friendship, and career frustrations.

Lister-Jones has an affinity for realism — she recorded the songs in one take, and uses that take on the soundtrack. So what you hear is what you’d get at an actual open-mic night at your local pub. To boot, what you hear in the couple’s bedroom and kitchen also has the atonal harmony of a flawed marriage, and it gives the movie verisimilitude.

Lister-Jones side-steps facile developments (don’t count on a record-contract bail-out) and stays doggedly within the reality of a shaky marriage in a way that is both admirable and taxing. By the 15th argument, we’re thinking that maybe a Hollywood ending wouldn’t be so bad.

But she stays true to her vision and, after some turbulence, guides the movie to a gentle landing. “Band Aid” acquits itself quite well as the first movie to be created and filmed by a crew comprising (almost) entirely women.

She even assigns to a woman (Susie Essman) the job of imagining what goes on in the head of a man when he is playing video games or watching sports.

They don’t come up with the correct answer (nothing), but it’s a brave attempt.

MOVIE REVIEW

“Band Aid”

Grade: B

Starring Zoe Lister-Jones, Adam Pally and Fred Armisen. Directed by Zoe Lister-Jones.

Unrated but has adult themes and language. Check listings for theaters. 1 hour, 31 minutes.

Bottom line: A down-and-dirty picture of a faltering marriage