In 1969, Sandy Denny was standing on the beach at Eden Mouth in St Andrews Bay in Scotland, watching a jet fighter swoop low over the sea. She stood frozen to the spot as it silently hit the water and was consumed under the waves. She had seen this beach a few months earlier. An entry in her diary from February records a nightmare featuring Harvey Bramham, the roadie for the group she was singing with at the time, Fairport Convention. In the dream, Bramham was persuading her to hold the wheel while he tinkered with the van's stereo. "On the righthand side of the road was the sea," Denny wrote, "and we were driving along the edge. The sea was black and choppy. The sky was stormy grey."
Two months later, Bramham was driving the van when there was a crash on the M1, after a late-night Fairport gig. It killed the band's drummer as well as the girlfriend of the guitarist Richard Thompson, with the other members suffering various degrees of injury. Denny escaped: she'd driven home separately with her boyfriend, Trevor Lucas. But the sense of foreboding lingered. The group's next album, Liege & Lief, a triumphant electrification of English folk music, would be her last with the group.
She turned all these premonitions and real and imaginary cataclysms into song. "Late November", which appeared on her 1971 album The North Star Grassman and the Ravens, encompasses all that's great about Denny's music: heaving with a slow, pitching swell, carrying a cargo of weird omens and morbid visions. So many of her songs from this period are set at sea or on wind-battered coasts, reflecting the enduring role the sea has played in British folk song. The folk canon abounds with shanties, press-gang songs, ballads of transportation and farewell, of superstition and of supernatural water beasts.
Unlike that of the 1960s in which Denny came of age, today's British pop music contains a high proportion of solo female artists writing and performing their own material or fronting their own groups. The critical reflex for such singers who appear vaguely "kooky" – Bat For Lashes, Alison Goldfrapp, Florence Welch – is to compare them to Kate Bush. Denny is more seldom invoked, which seems unfair, as she was the one who opened the way for others to follow.
Born in 1947 to middle-class parents in London's south-western suburbs, she later unsuccessfully combined a rock star's intense lifestyle – drink, drugs and long, lonely tours – with a yearning for domesticity and motherhood. She died – aged 32, of a brain injury resulting from a fall – in 1978, the year Kate Bush, the most iconic, unconventional and self-reliant female artist of the 1980s, released her first recordings (Bush namechecked her on Never For Ever).
Of the folk-inspired solo singers who were Denny's peers in the late 1960s – Anne Briggs, Shirley Collins, Beverley Martyn, Bridget St John and Linda Thompson (née Peters) – Denny achieved the highest profile and produced the largest body of self-written music. She was, in fact, the first British singer-songwriter presented as a solo artist in her own right. She left four albums under her own name, one with her short-lived group Fotheringay (a second unfinished one emerged in 2008), and also played a significant, defining role in the early years of Fairport Convention, the iconic group of the English folk revival. That group was still a wannabe West Coast psychedelic outfit when her induction as lead singer in 1968 ushered in a new raft of English folk songs, which in turn inspired the group to look to their homegrown culture and electrify the traditional canon – "Matty Groves", "Tam Lin", "A Sailor's Life", "Reynardine" and so on – most winningly on Liege & Lief.
But even as her bandmates were growing comfortable in this new skin, Denny had already tired of delving into the song archive at the English Folk Dance and Song Society for ballads to resurrect, and almost immediately on quitting the group in late November 1969 formed Fotheringay with Lucas and three others drawn from London's underground psychedelic scene. They were named after the Northamptonshire castle in which one of her historical heroines, Mary, Queen of Scots, had been imprisoned while awaiting judgment.
Denny's music has been anthologised, and even boxed up before, but there's been nothing to match the monumental scope of a new 19-CD set, simply entitled Sandy Denny. As well as all the remastered solo releases, the Fairport Convention and Fotheringay albums and various little-known contributions to film soundtracks, radio sessions and concert recordings, plus odds and ends such as her grandstanding guest slot on Led Zeppelin's Tolkienesque "The Battle of Evermore", this panoramic survey includes around 50 tracks which have never been heard since being laid down in the vaults by Island Records, the BBC and others between 1965 and 1978.
Her best-known song, "Who Knows Where the Time Goes?", along with Nick Drake's "Fruit Tree" and John Martyn's "Solid Air", are products of a peculiarly English strain of blissful autumnal melancholy. As a lyricist she wove together the threads of English lyrical balladry, her songs variously recalling the lovestruck troubadour ayres of Thomas Campion, the antiquarian romanticism of Tennyson, Christina Rossetti's windblown, regretful verse, and Thomas Hardy's tragedies. As a voice – she has an unforgettable breathy huskiness – she connected the dots between the folk songs of Kathleen Ferrier and contemporary revivalists such as Briggs and Collins.
Appropriately for one whose songs are loaded down to the Plimsoll-line with thalassic imagery and deep-sea turbulence, she was, according to her best friend Bambi Ballard, steeped in the maritime literature of Joseph Conrad, CS Forester's Hornblower series, and especially Master and Commander. "She was well read," Ballard says, "she had good grounding – Austen, Dickens . . ." And then there was the obsession with the Tudor and earlier eras, which was echoed in the cover painting of Fotheringay's 1970 album, in which she's depicted as a princess in floral gown. "We were all medievalists, that was the big thing at the time. The pre-Raphaelites were back in fashion, so all our drawings were reminiscent of that. I was making a lot of clothes, and used medieval patterns. Everybody got a dulcimer at one point . . . So in a way it was a very female sort of time. With hindsight, Sandy was one of the great groundbreakers."
There is, in Denny's music, an obvious tension between the nostalgic pull of the past and the desire to innovate. In "Who Knows Where the Time Goes?" she imagines herself on a "sad, deserted shore", watching migrating birds quitting their habitat according to some invisible signal, just like her "fickle friends". When she wrote these lines, the young Denny – she was 20 – could still hope: "So come the storms of winter and then the birds in spring again . . . I have no fear of time."
The life's work collected in the new box set invites speculation about where she might have been heading if she hadn't died in 1978. Her final album, Rendezvous, released in May 1977 but recorded 12 months before, now stands out as a neglected major work, whose true qualities have been obscured for decades by Trevor Lucas's over-zealous, "adult rock" production. In the box set you can hear, for the first time, Denny's demonstration recordings of these songs, uncluttered by the orchestrations, guitar solos and keyboard additions which Lucas slathered on: her rhythm guitar on "Still Waters Run Deep" is revealed as agile and propulsive, while her piano on "By the Time It Gets Dark" and "Full Moon" is stately.
There are strong links, too, with earlier English music traditions. The resplendently remastered "All Our Days" is an eight-minute mini-cantata that Denny wrote in explicit homage to the great English pastoral composers she loved. Its rich string masses recall the sumptuous sonics of Delius and Butterworth, but above all it is Vaughan Williams who is fêted here, with chords streaking like shafts of sunlight stabbing through clouds, and the alien ripple of a vibraphone recalling the mystical opening of the composer's Eighth Symphony.
At the other extreme, "Gold Dust" looks towards a funky, pin-sharp contemporary sound in the late 70s that might have rescued her at a moment when the organic folk-rock sound was being given a sound thrashing by punk. It's time to recognise Denny as not simply a folksinger but one of Britain's great poets of song.
Rob Young's Electric Eden: Unearthing Britain's Visionary Music is published by Faber. The Sandy Denny 19-CD box set is released by Universal Music.