In 1979, an interviewer asked Kate Bush — who had recently become the first woman to reach #1 on the UK charts with a self-written song, “Wuthering Heights,” at age 19 — “You’ve made it. What else is there to do?” Bush eagerly replied, “Everything!”

And she did. Bush, a cult figure in America who is regarded as a national treasure in the UK, created a legacy that has influenced countless musicians, many of whom might not even realize she made their work possible. How would most pop stars tour without the headset microphone, which was created for Bush’s 1979 Tour Of Life, using a wire hanger? Producing her own work in an industry in which a small percentage of women are producers, Kate Bush has maintained a level of control and integrity within her spellbinding music that few artists have matched. She opened the door for all artists, but especially women, to experiment more radically in their audio and visual work. As Imogen Heap once said, “When I was 17 and getting my first record deal, it was the likes of Kate Bush who had contributed to labels taking me seriously as a girl who knew what she was doing and wanted.” To be frank: Without Kate Bush, none of your faves would exist in the same capacity. That might sound hyperbolic, but there is so much, from turning live performances into multimedia, theatrical spectacles, to making music videos years before MTV’s debut, to wearing a swan dress — that Kate Bush did first.

Her groundbreaking legacy of experimental yet accessible, inspiringly individualistic work begins with the extraordinary debut album that turns 40 this weekend: The Kick Inside. Released when Bush was 19 in 1978, it included songs she had written as early as age 13 and introduced the world into Bush’s wild imagination. Arriving in a year otherwise dominated by disco and punk (“Wuthering Heights” replaced Abba’s “Take A Chance On Me” as the UK’s #1 single) this imagination felt “strangely out of time” and singular. The album’s focus on female sexuality, its use of voice as an instrument, and Bush’s unique storytelling techniques — particularly her exciting use of fluid narrative identity, in which she changes identities and narrative point of view with every song — created a new, unprecedented model for women in music. The Kick Inside (referred to as TKI from now on) made the world a safer place not just for women musicians but also for freaks and outcasts everywhere, and its anniversary is well worth celebrating.

Of course, first we need to address what will make most people either adore or despise TKI: That Voice. As the album begins, a wailing, impossibly-high-pitched voice grabs (or repels) the listener as it sings that opening line “mooooooviiiiiing straaaangeeeer.” Deborah Withers, author of Adventures In Kate Bush And Theory, wrote that the pitch of her voice is “an assault on the normal parameters of vocal modulation.” I feel it is no coincidence that, within a music criticism field dominated by straight white men, her most acclaimed album is 1985’s Hounds Of Love, on which her voice deepened enough for them to be able to handle it. Dismissive and condescending quotes from male critics about Bush’s early work, both from the ‘70s and now, are too numerous to collect here, but Suede frontman Brett Anderson’s assertion in the BBC’s The Kate Bush Story that in her early work she was “finding her way … she hadn’t quite found herself and all that early stuff of her dancing around in leotards is a little bit am-dram” (is he forgetting how he dressed in the early ‘90s?) and that Hounds Of Love is “the zenith” of her artistry, typifies the traditional critical approach to Bush’s work.

I disagree with Anderson and his ilk. Kate Bush wasn’t fumbling or “finding her voice” — TKI establishes her voice as not just a voice but also as an instrument. Throughout her entire career Bush almost never used backup singers, and instead created her own backing vocals herself by singing in different pitches, in discordant and revelatory ways. This is displayed to great effect on almost every TKI song: turn the volume way up and marvel in how the backing vocals on each song swoop upwards and swoon downwards to create a landscape seemingly independent from the main vocals, especially in “L’Amour Looks Something Like You,” “Moving,” and “Kite.” Bush uses her four-octave range as an instrument most famously and strikingly in “Wuthering Heights,” in which she sings in an almost dog-whistle-like pitch to embody the character of Catherine Earnshaw’s ghost in Emily Brontë’s novel. For most musicians, the voice is what they use to express words; for Bush, it is a remarkable tool that helps contribute to unique soundscapes.

Beginning with its title, which describes the sensation a pregnant woman feels as her fetus kicks, TKI is an album about bodies: the way they move (“Moving,” “Kite”), the desires they express (“The Man With the Child in His Eyes, ”“Feel It,” “L’Amour Looks Something Like You”), the way they both die and generate new life (“Room for the Life,” “The Kick Inside,”), and the way they sometimes return to haunt their lovers (“Wuthering Heights”). The album opener, “Moving,” invites listeners to move in order to free their minds: “As long as you’re not afraid to feel… Don’t think it over, it always takes you over/And sets your spirit dancing.” The importance of movement and the body is crucial to TKI, especially because Bush herself trained in dance prior to its release and performed elaborate, endearingly earnest dance routines in her performances and videos. Bodies and movement are an unusual focus for any album, much more so from one by a teenage British girl in 1978.

Reared in the country known for stiff upper lips and repressed sexuality (full disclosure: this author is part-English), Bush sang frankly in songs written in her teens about lust, and her narrative voice on TKI possesses an active feminine, sexual gaze. In the album’s second song, “The Saxophone Song” she imagines herself “in a Berlin Bar” as she watches a saxophonist play and becomes a voyeur filled with desire, a traditionally masculine position. On the album’s second half, Bush becomes franker, and downright explicit, about her active sexuality. In “Feel It,” she and her lover go “back to your parlour” where “Locking the door/My stockings fall onto the floor, desperate for more.” She stretches out the word “more” with her inimitable voice for as long as she can, mimicking the sound of a woman in ecstasy. She then sings, “The glorious union, well, it could be love/Or it could be just lust, but it will be fun/It will be wonderful.” In case there was any doubt that Bush was singing about sex, she then explicitly describes penetration: “keep on a-moving in, keep on a-tuning in/synchronize rhythm now.” What teenage girl was celebrating the “fun” of a possible one-night stand in pop music in 1978, much less the “sticky love inside” (a cringeworthy lyric, yes) it produces in “L’Amour Looks Something Like You”?

TKI is also revolutionary because it establishes Bush’s narrative style as fluid and multiple; her songs are short stories each written from a different narrator’s perspective rather than from her own point of view. This writing style stands in stark contrast to the traditionally personal style of music focusing on love and heartbreak that continues to dominate the charts. “I often find myself inspired by unusual, distorted, weird subjects, as opposed to things that are straightforward. It’s a reflection of me, my liking for weirdness,” she said in 1980. Unlike the majority of pop/rock artists, The “I” in Bush’s music is rarely Bush. Her songs are not confessional, but are rather short stories told from the points of views of a diverse range of narrators. From Bush’s songs, we can know about themes that interest her, but Kate Bush herself rarely speaks in her work; her narrators, who occupy multiple genders, races, and historical times, do instead. This is a deeply radical break from traditional “confessional “ songwriting, especially for women up to that point. Consider that the most acclaimed female musician of the time, and probably of all time, Joni Mitchell, is most-lauded for her confessional album, Blue.

“That’s what all art’s about — a sense of moving away from boundaries that you can’t in real life,” Bush said, explaining her writing technique. “Like a dancer is always trying to fly, really — to do something that’s just not possible.” As a result, Bush’s ever-changing but always unusual topics on this and all her albums enraptured many outcasts, weirdos, and freaks, and created space to, as she sang on her later album The Dreaming’s “Leave it Open,” “let the weirdness in” to popular music. Rufus Wainwright summed up her appeal for outsiders when he said, “She connects so well with a gay audience because she is so removed from the real world. She is one of the only artists who makes it appear better to be on the outside than on the inside.”

The song that perhaps best captures what makes TKI revolutionary is its title track, which merges all the aforementioned topics: use of voice as instrument, feminine agency, and Bush’s fluid, narrative-story writing technique on unusual topics. “The Kick Inside” is based on the English folktale “The Ballad of Lucy Wan,” in which a brother impregnates and then decapitates his sister. Bush’s take on the story is sneakily radical, especially from a feminist perspective. In the folktale, the sister only speaks briefly before her brother kills her, but Bush rewrites the story from the sister’s point of view, literally giving voice to a history of women silenced by male violence, and changes the story so that the sister actively chooses her own death instead of being her brother’s victim. Bush said in 1978, “The sister becomes pregnant by her brother. And because it is so taboo and unheard of, she kills herself…The actual song is in fact the suicide note.” While the death is still tragic, the fact that Bush re-envisions a violent narrative passed down through centuries of patriarchal generations from a woman’s point-of-view and places the story’s narrative action in the woman’s hands is a subversive act.

One might say that this act of feminist re-visioning parallels the narrative of Bush’s own career. Instead of drawing from normalized, “feminine” confessional-based musical forms, she created odd, polarizing sounds with her voice to tell stories of “Strange Phenomena”, and later took complete sonic control over her work as a producer and multi-instrumentalist in a still-predominantly male-dominated industry where women are often denied agency or forced to compete with one another (Britney vs. Christina, anyone?). Bush co-produced 1980’s Never For Ever, which was the UK’s first #1 album by a British female solo artist, and started producing her work completely on her own for the rest of her career starting with her 1982 masterpiece The Dreaming. Over the course of her career she has continued to break records: in 2014, she became the only artist besides the Beatles and Elvis Presley to have had eight albums simultaneously on the UK’s top 40 chart, and her 2014 Before the Dawn live shows — her first live performances since 1979 — sold out in minutes.

Perhaps most importantly, beginning with The Kick Inside she has inspired a wide array of artists to “let the weirdness in.” Lady Gaga covered Bush’s duet with Peter Gabriel, “Don’t Give Up,” because she wanted to “make something that young people would hear and learn something about Kate Bush”, and her theatricality has its roots in Bush’s so-bizarre-they’re-brilliant live performances. Björk frequently cites Bush as a pivotal influence on her musical “form”, saying “I remember being underneath my duvet at the age of 12, fantasising about Kate Bush,” and even sent Bush of a demo of herself covering Bush’s “Moving” in 1989. Lorde played “Running Up That Hill” before the shows on her Melodrama tour, and Bat For Lashes’ Natasha Khan said of Bush, “As an artist myself, [she’s] helped me to not be frightened to put my vulnerability as a woman [in my work] and in that, be powerful.” Bush’s influence is also felt in hip-hop, especially due to her early use of sampling, best seen in her sampling of the Gregorian chanting from Werner Herzog’s film Nosfertu The Vampyre in Hounds Of Love’s “Hello Earth.” One of her biggest champions is OutKast’s Big Boi, who has repeatedly called her “my favorite artist of all time,” and Tricky from Massive Attack said of Bush’s song “Breathing,” which features the line “breathing my mother in,”: “I’m a kid from a council flat, I’m a mixed-raced guy…totally different life to Kate Bush, but that lyric, ‘breathing my mother in,’ my whole career’s based on that.” Even Chris Martin “admitted” that Coldplay’s “Speed Of Sound” “was developed after the band had listened to Kate Bush.”

Countless other artists, ranging from Tori Amos to St. Vincent to ANOHNI, have cited Bush as a foundational influence, and she has inspired a rabid global following of fans to embrace the wild, imaginative, limitless nature that her music embodies and represents. Beginning with her groundbreaking debut, 40 years later the world has been indelibly altered by Kate Bush’s impact, not only in music but also in the hearts of all fans whose lives her work has enriched.