As debut singles go, Wuthering Heights - the first British No 1 written and sung by a woman - had a huge effect in shaping Bush's career.
Not only did it establish her as a unique - and easily parodied - performer, but it indelibly associated her with voices from beyond the grave.
Since then, even in her spandex and batwing years, she has often appeared as much medium as message, channelling spirits that seem slightly beyond her control.
She memorably monologued Molly Bloom's climax from Ulysses in her song Flower of the Mountain, after being granted the rare tribute of authorisation from the James Joyce estate.
Now 53, she has always given the impression of waiting to be filled with inspiration before letting it go in a rush; albums have often seemed to be released in a psychological as well as a literal sense.
Her "Christmas" CD, which comes out on Monday, 50 Words for Snow, is no exception.
American crime writer Elmore Leonard has 10 golden rules for writing.
Chief among them is: "Never begin with the weather."
Rarely can a piece of work have so directly contravened that law as Bush's album.
The opening track, Snowflake, proceeds as advertised: "I was born in a cloud, now I am falling..."; in the hour or so that follows, the listener is not invited to stray beyond the muffled winter wonderland that results.
Bush's Ice Queen persona emerges - for a portentous 11 minutes - from beneath the frigid waters of Lake Tahoe in the second track; with blizzards whistling around the edges of the songs she then gets it on with Frosty the Snowman who alarmingly arrives (colder than Cathy Earnshaw) through an open window and proceeds, not surprisingly given her amorous attention, quickly to melt in her bed.
Subsequently seeking, but not finding, greater commitment, she falls head over heels for a yeti.
Still not content - and no stranger to restless yearning - she gets herself holed up for the holidays in a somewhat slushy duet with Elton John before apparently forcing Stephen Fry to enunciate the made-up Inuit intuitions of the album's title: snow becomes, in Fry's stage whisper, "blackbird Braille" and "hunter's dream" as the Narnia-voiced Bush cajoles him to greater linguistic effort.
All this is done if not quite fully in earnest, then - appropriately for someone who was originally discovered on a demo tape by Pink Floyd's Dave Gilmour - with a good deal of 70s concept album bravado.
But then Bush's diehard legion of fans, who include a fair few seen-it-all pop critics, would expect nothing less. In recent decades, Bush has not been the gift who has kept on giving.
From her 1993 album Red Shoes, a musical reimagining of the Michael Powell and Emeric Pressburger film, there was a 12-year gap until the much-feted eight tracks of Aerial in 2005 (most critics judiciously overlooked the 42-minute accompanying bonus CD which involved a long and operatic interpretation of the genesis of a Rolf Harris painting, during which the Aussie dauber occasionally rapped).
After that, nothing until this year, which has seen an album, Director's Cut, that reworks two 80s collections, and now the new meteorological meditation.
The adjective that has always snagged on Bush, with the requisite "ethereal", is "guileless". She follows, we are invited to believe, her instincts in a childlike way.
Her contrivances are, in this reading, anything but contrived. In some of this, you might argue that her silence has been a powerful ally. The air of mystery that she conjured as a 19-year-old has been preserved by the parsimony of her output.
Bush has successfully tapped into the media's working definition of a recluse: someone who has no particular desire to be interviewed for magazines.
In the 12 years she took off from working, she appears to have simply been taking time to be with her family, her long-term partner and guitarist, Danny McIntosh, and her son, Bertie, now 13; living in some rural style at their two houses - one on a clifftop in Devon, the other on a piece of land that takes in a small island on the River Kennet in Berkshire.
While her fans dwelt on the Jungian symbolism of her retreat, and the tabloids occasionally concocted comically unfounded rumours about "16-stone Kate", the possibility persisted that for a while she simply didn't have much to say.
When she "re-emerged", in 2005 with Aerial, it was to sing about the joys of Bertie; about the pleasures of her domestic routine (few artists have ever found comparable lyrical inspiration in washing machines); and, movingly, about the death of her mother, in her haunting song, The Coral Room.
Maternal emotions run deep in Bush's music (her first album carried the resonant title The Kick Inside).
If her power once came from her mother, it now seems to be rooted in her own identity as a mother.
She has always wanted to keep these feelings close, protecting the child within in every sense, and to dramatise them on her own terms.
Bush, famously, toured only once, in 1979. It was a costume-rich, 28-night European song-and-dance venture. "By the end," she recalled, "I felt a terrific need to retreat as a person, because I felt that my sexuality, which in a way I hadn't really had a chance to explore myself, was being given to the world in a way which I found impersonal."
She took control of her albums and promotion, worked from a studio near her home, managed to avoid the stereotypes her record company, EMI, might have imagined for her, and never again went on the road.
In her occasional interviews, Bush says little that is not bland, intentionally or not.
Her interviewers come away with an impression of "niceness" (a report in the Washington Post last week described her as the "English equivalent of a soccer mom").
Musically, though, she is claimed as the inspiration for every vocal artist from Bjork to Florence and the Machine.
Happily, she seems to be finding a way to write again.
You can see why she might have been drawn to the possibilities of snow. She likes the idea of being here today and gone tomorrow, of music being about transient states rather than all-consuming life; and you either catch her drift or you don't.
*50 Words For Snow is out on Monday
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