Esther Williams gave Christine Lavin the OK last week. Yes, the Hollywood movie star of the 1940s and ’50s said she was fine with Lavin using her image in a video accompanying Lavin’s new song, “When Cary Grant Made Movies.” Williams’ email, written with her husband Edward Bell, added:

“Thank you, Christine, we believe this song HAD TO BE WRITTEN! AND MUST BE HEARD!”

The caps are all Williams’.

The song is Lavin’s latest against gun violence in this country. Gun deaths are nothing new to America: 30,000 citizens die each year.

We’ve also had a run of high-profile murders in recent weeks. An NFL player shoots his girlfriend, then takes his own life. A disturbed 20-year-old steals his mother’s guns, kills her, shoots 20 kids and six adults at a school in Newtown, Conn., then takes his own life. And here, authorities say a felon set a neighborhood on fire, shot four Webster firemen responding to the fire, killing two, then took his own life. The body of a woman presumed to be the felon’s sister was also found by investigators.

“The Newtown shooting was bad enough,” Lavin says. “But the Webster shooting was almost worse. What can be worse than shooting children, than shooting firemen? This can be a real tipping point for the country.”

The folk singer considers western New York home, or one of them: She has many friends and relatives in the area, went to school at The College at Brockport, and has lived in Geneva from time to time, most recently for the past 21/2 years while taking care of her aging mother. Her mother has dementia and recently broke a couple of bones in a fall, so this summer she went into a long-term care facility; Lavin moved back to New York City.

Folk singers are frequently issue-oriented and — along with liking knitting and singing about bad relationships — Lavin considers gun violence one of her issues. She was talking by phone last week, having spent the day in her pajamas after finishing her “Just One Angel” holiday, which included a stop in Old Saybrook, Conn., on the day of the Newtown shootings. The promoter opened the show with a few remarks about the violence, and a moment of silence was held.

And Lavin already had a song ready about guns, “One Million Americans,” a number that she calls “a cold, hard statistic.” One million is the number of Americans who had died by gun violence — murder, suicide, accidents — in the years following the assassinations of Robert Kennedy and Dr. Martin Luther King, Jr. Since that song was written in 2007, following the Virginia Tech murders, that number has soared past 1.12 million.

But Lavin didn’t sing “One Million Americans” on the night of the Newtown murders. “I knew I couldn’t get through it without crying,” she says.

Less than two weeks after the Newtown shooting came the one in Webster. Lavin sat down that night and wrote and recorded another song, accompanying herself on gentle guitar, then put together a video and posted it on YouTube.

It is a short song, just 90 seconds, but “When Cary Grant Made Movies” poses an interesting question. “When Cary Grant made movies, men wanted to be like him,” she sings. “When Esther Williams made movies, the whole world lined up to swim.” Indeed Williams, an Olympics-level swimmer before she dived into her movie career, had a line of swimsuits back in the day — a swimsuit line, Vanity Fair magazine pointed out in a story last spring, that was back in vogue. Lavin’s point is that media and culture hold a huge sway on our thinking. Fred Astaire made people want to take dance lessons, she says. Julia Child inspired Americans to cook beef bourguignon.

“Yet when Angelina Jolie makes a movie, and her co-star is a gun,” Lavin sings, “we’re supposed to believe that violent images” — and here her voice takes on an inflection of disbelief — “don’t influence anyone?”

Lavin punctuates the point with a Cary Grant cigarette advertisement, and closes with a chilling image of the Virginia Tech shooter holding two guns, posing as though he were in a movie ad.

Lavin immediately sent links of the video to friends in the folk world. And Williams, now 91 years old. They approved. And her friend, the actor Jeff Daniels, who’s also a musician. “He has a funny song about being blown away by Clint Eastwood,” Lavin says. “But he sent me an email that said Hollywood has to admit that it’s a part of the problem.”

Her anti-gun beliefs do cause Lavin grief. She gets her share of emails.

“A lot of times I don’t read them because it’s from someone who’s just crazy and angry and it just ruins my sleep,” she says. “When someone does ask me about it, I just say, ‘Listen to the song, I just give statistics and ask questions.’ And then I tell them, ‘Don’t shoot the messenger.’ Of course, if they did shoot the messenger, my record sales would go up and everybody would hear the message.’ “