At 70, the singer-songwriter who has always been unafraid of difficult subjects is releasing a final album, “The Light at the End of the Line.”On a recent morning, Janis Ian spoke expansively from her work space in Florida about a 50-year career marked by literary lyrics, social activism and major hits. Just one subject brought her up short. When pondering younger artists who’ve publicly cited her as an inspiration, she paused and threw up her arms. “I can’t think of one. So many people say, ‘Joni Mitchell is my big influence,’” she said. “And I thought, wait a minute. Didn’t I influence anybody?”She might not get the loudest shout-outs, but there’s no denying that Ian has often served as a cultural clairvoyant.In 1967, she became one of the first fully self-determined female singer-songwriters in pop, having penned every track on her debut album, which was released one month before Laura Nyro’s, a year before Joni Mitchell’s and three before Carole King’s.The subjects she became most famous for writing about, outliers at the time, have since become ubiquitous. Her breakthrough hit, “Society’s Child,” written in 1965 when she was 14, was one of the first charting songs to center on an interracial romance. Her biggest score, “At Seventeen,” which reached No. 2 in 1975, confronted lookism and bullying with a candor that anticipated the work of contemporary artists including Billie Eilish, Demi Lovato and Lizzo. Ian was also one of the first gay pop stars to come out in the early ’90s, and she championed free downloads as a promotional device back when the industry did everything it could to shut them down.Ian had few role models for her self-determined path, citing only Nina Simone and Victoria Spivey, a blues singer and writer who made her first impact in the 1920s. Otherwise, she said, “everything was male-identified.”“Plenty of other artists have a gift for melody and vocals and great lyrics,” Ian said. “The only thing I think I do better is to talk about things that people have a hard time voicing. I give them a safe way to voice them.”Michael Ochs Archives/Getty ImagesThe disparity between the world in which she carved her path and today has been on Ian’s mind lately because of a major decision she made in the last year. At 70, she will release her final album, “The Light at the End of the Line,” this Friday, followed by a valedictory tour. “I’m done,” she said, with a mixture of relief and anticipation. Ian said the wear and tear of serving as her own manager and song publisher, along with life as a touring musician, left little time for the thing she loves most.“I’m a writer first,” she said. “I care desperately about writing — any kind of writing.”That includes haiku, short stories and a novel she hopes to finish in her coming life. She’ll work on everything in a nearly completed addition to her home, on an island in Tampa Bay where she lives with her wife of 19 years, Patricia Snyder, a retired criminal defense lawyer.Her final songs have a summary mission. In the title track, an elegant acoustic ballad, she bids adieu to her fans. “Some of them have stuck with me for 56 years,” she said. “That’s longer than I’ve known most of my family.” In “I’m Still Standing,” the stalwart melody underscores lyrics that embrace the physical changes brought by time, which, Ian said, explains the white hair and lack of makeup she proudly sported in our interview. In the classically influenced piano piece “Nina,” she salutes one of the artists she most admires, her friend, Nina Simone, who cut a bracingly rueful version of Ian’s song “Stars” in 1976.“Nina was so complicated,” Ian said. “She could be the most astonishing friend and also the most horrible person. But, as a solo performer, she was the single best I’ve ever seen.”Some of the new songs are more expressly political. “Perfect Little Girl” extends the theme of “At 17,” while in “Resist” she repurposes the social protest of earlier songs with lyrics that, among other things, use raw language to capture the violence of female genital mutilation. As with “Society’s Child,” some radio stations have told her they won’t play it. “They said it’s too suggestive,” Ian said. “Is the song sexual in some way I’m not aware of?”Ian was reared to raise such questions. Her father, a music teacher, and her mother, a secretary at a college, ran a progressive summer camp in upstate New York. Because of her parents’ politics, the FBI tapped the family phone, tracked their activities and discouraged schools from hiring her father, which she wrote about on the 2000 album “God and the FBI.”Ian’s upbringing in the mainly Black area of East Orange, N.J., helped inspire her to write “Society’s Child” in 1965, one year after the Civil Rights Act was passed. Her producer, Shadow Morton, a key shaper of the girl group sound, had a deal with Atlantic Records that financed the recording, but the label declined to release it. Ian was never told why, though she said Jerry Wexler, the Atlantic president at the time, later apologized for the decision. Verve Records picked up the song and released it twice in 1966, without success.A major break came the next year when she was invited to appear on a CBS-TV special, “Inside Pop: The Rock Revolution,” for which the host Leonard Bernstein used his enormous cultural currency to lend legitimacy to the explosive new music of the ’60s. Ian said her song “wouldn’t have gone anywhere without the show.” Yet its focus on race scared off enough radio stations to halt its charge up the Billboard chart at No. 14.After “Society’s Child,” Verve released three more Ian albums that failed, but in 1973, Roberta Flack covered her song “Jesse” and scored a hit, which helped Ian get a contract with Columbia Records. “Janis Ian wrote songs that touch my heart,” Flack wrote in an email. “She tells stories in her songs that many of us can relate to — tender experiences that help us articulate what we feel about how the world treats us in so many ways.”Ian’s second album for the label, “Between the Lines,” featured “At Seventeen,” with lyrics capturing the naked shame Ian felt at being considered “an ugly duckling” with an honesty so brutal, it made some people uncomfortable — including its author. “That song was scary to write and scary to sing,” she said. “I would sing it with my eyes closed because I was so sure the audience would laugh at me. It was astonishing to me to realize, first, that they weren’t laughing. And, second, that it applied to boys too.”The song’s nuanced and erudite lyrics also accounted for the loss of self that can be suffered by women considered the most desirable — the very type who bullied Ian. “Their lives are an eternal beauty contest,” she said.Ian believes her willingness to write about uncomfortable subjects has become her métier. “Plenty of other artists have a gift for melody and vocals and great lyrics,” she said. “The only thing I think I do better is to talk about things that people have a hard time voicing. I give them a safe way to voice them.”Though Ian finds it distressing that the difficult subjects she has written about remain relevant decades later, as she prepares to leave the music business, she believes the world has changed considerably from when she started. “It’s too easy to fall down that rabbit hole of saying ‘nothing has improved,’” she said. “I can no longer be arrested in this country for being gay. That’s a huge difference. I firmly believe that things work out the way they’re supposed to. Whether that will be in my lifetime, I don’t know. But I do believe things will be better.” More