When musician and film-maker Carla Easton was growing up in Lanarkshire, Scotland, in the 1990s, her favourite girl band were Jem and the Holograms – the animated protagonists of a US cartoon. Easton would have liked real musical role models to look up to but didn’t know where to look. Nor how close to home she might have found them.

She didn’t have posters of the McKinleys on her bedroom wall, even though the Edinburgh sisters toured with the Beatles and were the first girl band to play Wembley. She had never heard of them – nor the Ettes, Scotland’s first all-female punk band, nor Strawberry Switchblade, the Glaswegian duo who remain the only Scottish girl band ever to crack the UK Top 10. Nor the Twinsets, nor Sophisticated Boom Boom, nor Lungleg.

You may not have heard of these pioneering Scottish musicians either, but Easton’s documentary Since Yesterday: The Untold Story of Scotland’s Girl Bands aims to change that. “Decade after decade, there are all these brilliant women. Why are they not remembered?” Easton asks.

Aside from occasional radio and TV spots, many Scottish girl bands were either ignored or not taken seriously by a London-centric music industry and media, and then faded into obscurity at home, too. Even the National Museum of Scotland’s 2018 exhibition about Scottish pop didn’t tell their stories. Easton discovered that many of these bands hadn’t even heard of each other.

In 2018, she and collaborator Blair Young began interviewing them and asking their fans, via social media, to unearth memorabilia. While TV and radio performances languished in broadcasters’ archives, the histories of these groups were chiefly kept by fans in boxes under beds, and by the musicians themselves. So the documentary became a digitising project, with Easton and her team determined to protect the 15,000 artefacts they received.

This week, after crowdfunding almost £30,000 to be able to license those old broadcasts, Since Yesterday will premiere at the Edinburgh international film festival, with the musicians in attendance. The film chronicles 50 years of music, beginning with the McKinley sisters and ending with 00s rock band the Hedrons, who raged against indie sleaze-era misogyny as they tried to break into the mainstream.

“God, I wish I’d seen them on TV when I was young,” Easton says with a rueful grin. “There were real bands!” She is quick to credit the many great Scottish bands fronted by women – as well as the (non-Scottish) Spice Girls and their pop domination in the late 90s – but she had to form her own band, TeenCanteen, to see a stage filled with Scottish women and their instruments. “I hope that a lot of women and non-binary artists see this film and think, ‘I can do that too.’ Everyone in it has pushed through on their own terms; no one compromised.”

That’s certainly true for Strawberry Switchblade, whose 1984 hit Since Yesterday – which spent 21 weeks on the UK singles chart – gives the film its title. With its sparkly synths and sugary la-la-las, it has often been mistaken for a bittersweet love song, but Rose McDowall, who formed the group with Jill Bryson, cackles at the thought. “It’s about nuclear war! I was terrified of war because I had a baby. But that’s how our brains worked; you can love pretty things and be dark at the same time.”

Just as their song was misunderstood, the duo’s vibrant aesthetic – polka dots, hair ribbons, makeup dramatic enough to make Robert Smith blush – led to criticism from the media and their record label. From headlines like “Strawberry Tarts” to meetings with Warner about “taming us”, as McDowall puts it, they felt boxed-in and pressured. “We’d been dropped into this place where everything was alien,” McDowall says, describing the experience of leaving a turbulent Glasgow suburb for limousine rides to Top of the Pops. “It just didn’t feel real.”

McDowell says Warner wanted to fit them into a mould shaped by the Bangles and Bananarama – “but I wanted to be Patti Smith”. Ryuichi Sakamoto was interested in producing their second LP. But the label pressure combined with mental health struggles led to Switchblade splitting just one year after releasing their debut album.

Their story fits into a familiar pattern for Scottish girl bands who, in order to make it, had to move to London and become cut off from their supportive local scenes. Plenty of others “were dropped, or not managed, or not paid,” says Easton, pointing out that the McKinleys claimed that at the height of their fame they could barely afford to buy chips. “Other bands had to change their sound, or how they looked. They got pregnant, or labels feared they might get pregnant.”

Such was the fate of 80s post-punk group Sophisticated Boom Boom, who supported Simple Minds and bagged John Peel sessions with their witty, stylish songs. Before they could get signed, singer Libby McArthur found out she was pregnant. In the film’s saddest moment, she recalls telling the group, and later discovering that her bandmates had replaced her. “The loss was devastating,” she says, “but I went out with my chin up. The one thing I decided was, you will not use that name. Sophisticated Boom Boom – you owe me that.”

Come the 90s, Scotland’s girl bands were rejecting the promises of London-based labels and a fickle music press. Inspired by US grunge and riot grrrl feminism, a scene of DIY labels, zines and all-female charity gigs sprung up in Edinburgh and Glasgow, featuring bands such as Lungleg, Hello Skinny and Pink Kross. Many musicians credit Saskia Holling, who also played in Sally Skull, for gluing the scene together, though she protests: “I would never have called myself a promoter.” Her first gig night, called Twisted Girl Pop Dream, was held in 1993, showcasing a wild array of genres and styles; rooted in community. “We were like, ‘We can do this in our own way, and support each other,’” Holling says.

The bands who did try to go down a traditional label route found women were still being pitted against each other. Lesley “Soup” McLaren, drummer of the Hedrons, recalls with disbelief how their manager couldn’t get them a record deal for fear they might get pregnant – a paranoia still strong in the mid-00s. “It was seen as a risk to take a punt on four girls. Those A&R guys were all too bloody spineless!”

The Hedrons played over 150 gigs in 2007, a relentless schedule designed to hone their craft and win over crowds. Their exhilarating stage antics secured them a runway gig at New York Fashion Week (“It was tartan week,” she sighs) and a support gig for the Sex Pistols (“We met Johnny but he had his minder with him – I don’t know if he thought four girls from Glasgow were gonna jump him”). At the Isle of Wight festival, knowing that Channel 4 were filming, the band encouraged singer Tippi Hedron to “steal” the main stage runway reserved for Mick Jagger. “She turned to me and said: ‘Will I go?’” laughs McLaren. “Aye! Go on!”

Their attitude drew industry tastemakers such as Seymour Stein to their shows, but even the man who signed Madonna wouldn’t offer them a record deal. Eventually the Hedrons shelved their second album and walked away. “We wanted to be taken seriously,” says McLaren. “I thought, ‘It’s going to be another 10 years to break this band, earning £10 a day.’”

The documentary doesn’t feature contemporary bands such as Honeyblood (one of the few Scottish girl bands to release a second album) or Sacred Paws, the only female and non-binary group to win the Scottish Album of the Year award. Instead, Easton uses the film to highlight grassroots organisations including songwriting collective Hen Hoose and the gig series Amplifi, and to emphasise the recurring gender imbalances and exploitative working conditions reported this year in the UK government’s depressing Misogyny in Music report. “The top-down isn’t going to do it,” Easton says, referring to the traditional music industry. “So we need to get behind these grassroots organisations and show there’s a demand – and that there needs to be financial support.”

Since 2014, she estimates that more than 50 new girl bands have sprung up in Scotland. “What happened? The first ever girl rock school happened,” she says. Both Easton and McLaren mentor at RIG Arts’ Rock School project in Greenock, an area among the most deprived in Scotland. They give free music lessons and help young people with songwriting and promotion. Teenage sisters Eva and Grace Tedeschi, AKA the Cords, have already had BBC airplay and will support the Vaselines on tour. “They’re doing all the things I was shouting about,” beams McLaren. “Get out there! Get in a band!”

It’s still far from an easy path, but the Cords have generations of Scottish girl bands standing proudly behind them. Since Yesterday is the rare documentary that has created a historical archive but also boosted an active community from which Scotland’s next girl band may spring. As McDowall says: “We’re not going to lay down, are we?”

• Since Yesterday: The Untold Story of Scotland’s Girl Bands premieres at the Edinburgh international film festival on 21 August, and is on general release in Scotland beginning 18 October

• This article was amended on 22 August 2024 to clarify that Honeyblood is not the only all-female Scottish band to release a second album.