It has never been easy for women in the music industry. Once upon a time the evidence was largely anecdotal. Now it’s being recorded for posterity, frame by frame. Recent documentaries about Britney Spears and Demi Lovato exposed the trauma inflicted on post-millennial pop stars. Two new portraits of Anna Mae Bullock and Marianne Elliott-Said, better known as Tina Turner and Poly Styrene from punk group X-Ray Spex, ponder the price paid by their forebears.

Turner’s story feels archetypal, a tale extracted from deep within the DNA of showbusiness. An abandoned child — ‘my mother didn’t like me’ — from a poor Tennessee background, the opportunity to fulfil her gifts came with the classic caveat: subjugation by an older, controlling man. Rock’n’roll pioneer Ike Turner romanced her while she was still at school. Furs on Saturday night, church on Sunday morning, arithmetic on Monday afternoon. So it goes.

She rose to fame in the late 1960s in the Ike & Tina Turner Revue, the lit fuse at the centre of a powder keg of supercharged R&B. With her soulful rasp, lioness’s mane and powerful physicality, on stage Turner was imperious. Off it, she suffered years of horrifying abuse at the hands of her husband. Half a century later, Turner sits in her palatial Swiss home and shivers: ‘I was insanely afraid of that man.’ In 1976, tired of ‘living a life of death’, she escaped across a Dallas freeway to a Ramada Inn with 36 cents in her purse, and never came back. Ike got everything. She took nothing but her stage name.

The most compelling parts of Tinatell this — by now familiar — story. Turner’s happy ending, while thoroughly deserved, is less dramatic. Her transition to AOR 1980s star made for largely uninspiring music, but few could begrudge a forty-something woman of colour the chance to fill stadiums around the world. ‘It wasn’t a comeback,’ she says, ‘because I had never arrived.’ Turner retired in 2009, two years after Ike’s death. Her eternal ‘curse’ is to still have to talk about him.

Tina is a redemption song, conventionally sung. Constructed from new interviews, old audio and often thrilling archive footage, its no-nonsense mix of grit and polish complements its subject. I Am A Cliché offers something more opaque. Narrated, co-written and co-directed by Poly Styrene’s daughter Celeste Bell, it’s an act of personal retrieval. Poly died of cancer in 2011, aged 53, while Bell was still constructing a relationship with a mother who ‘certainly neglected my needs at times’. Her aim is to ‘[build] a picture of who she had been before me’.

Who does she discover? A woman for whom ‘Identity’ wasn’t simply a song title, but the defining issue of her life. Caught between the black of her absent Somali father and the white of her British mother, Poly Styrene felt like a misfit even among the outsiders of punk.

A hippie teen runaway inspired by the Sex Pistols, she formed X-Ray Spex to sing/shout strange, prescient anti-consumerist songs like ‘Germfree Adolescents’ and ‘Oh Bondage Up Yours!’. Her mere presence challenged conventions. We see her on Top of the Pops, charismatic and charming, scrappily stylish, braces on her teeth. One interviewer introduces her as ‘hardly Linda Ronstadt’; another asks whether she intends for people to laugh at her.

A hyper-sensitive soul for whom ‘every romance ended in tears’, the attention scoured away her fragile sense of self. Damaged by a bad drug experience in New York, she left the band in 1979. After shaving her head in John Lydon’s bathroom — a chilly foreshadowing of Spears’s breakdown 30 years later — she was sectioned after claiming to see a UFO. ‘The first time she saw herself singing on telly,’ says Bell, ‘she was in a psychiatric ward.’ Aged 21, she was told she would never work again.

Life thereafter followed a ‘constant cycle of elation and despair’. Joining the Hare Krishna movement instigated a third name change — Maharani — but no escape from herself. Eventually, her daughter was removed from her care. ‘She pushed me down the stairs once and I never let her forget it,’ says Bell, with a smile in her voice. Later, they were reconciled. Bell was heavily involved when Poly Styrene returned to making music towards the end of her life.

Her diary entries, read by Ruth Negga, suggest a funny, dreamy, difficult, determinedly unknowable soul. Captured here in fragments rather than face on, her influence, at least, feels tangible. ‘Her voice was an awakening,’ says Neneh Cherry. ‘I started singing because of her.’

In Tina, Turner exclaims: ‘The world! That’s where I wanted to go.’ Via very different approaches, both films illustrate what a perilous mission that could, and can, be.