While kids and teenagers are still lining up for superhero movies and sci-fi sequels, this is part of Hollywood's continuing effort to revisit and celebrate its own history for adult audiences.

If you're from my generation you probably don't know the details of Judy Garland's life, just that she was a train wreck thanks to substance abuse (I have a vague awareness that she did a few concerts in Australia, one of which she was too drunk to finish). This movie goes into specifics to tell you why and how she ended up.

It looks at a period about six months before her tragically early death when she took a gig in London performing a series of shows of her hits because of how broke she was.

It was the 60s and pop culture had moved on from the show tunes era of Hollywood's Golden years, and when we meet Judy (Renee Zellweger), she's not exactly washed up, but when the hotel she's been staying at with her kids (one of whom is Bella Ramsey, Ellie in The Last of Us) won't let her back in because she hasn't paid her bill she has no choice but to deposit them with their father, her ex husband and former manager Sid (Rufus Sewell).

She then goes to a lavish Hollywood party where she'll stay all night, probably intending to get too trashed to go home and with no home to go to in any case.

American audiences – and investors who might otherwise back her career – have cooled on her because of the reputation about how unreliable she is, so when the offer comes from the UK, she's very reluctant to leave her kids behind but does it anyway.

So it's her UK financier Bernard (Michael Gambon) and PA Rosalyn's (Jessie Buckley) turn to suffer her drunkenness and anxiety. Either sloshed or hopped up on amphetamines, Judy suffers crippling performance anxiety and it's up to Rosalyn to drag her into hair and make-up and just about shove her onstage.

It's when she gets there that the magic happens, Garland coming to life and belting out her hits like a seasoned pro, the stage obviously the only place she's ever truly at home and happy.

But even that can't hold her mental and chemical abuse problems at bay for long and Londoners soon learn how flinty and capricious Judy is. Amid a whirlwind romance with her latest beau, nightclub owner Mickey (Finn Whitrock) that goes south as soon as it blossoms, the race is on to just get Judy to the end of the tour.

And throughout it all, we see flashbacks to Judy's young Hollywood days and the abuse the star system put pretty young girls like her through.

At the behest of legendarily feared MGM boss Louis B Mayer, Judy is plied with drugs to discourage her from eating to retain her youthful figure, her love life (including a date with longtime costar Mickey Rooney) is carefully monitored and controlled, she sometimes isn't even allowed to sleep because of her punishing schedule and there's a very predatory scene that alludes to the sexual abuse the real Garland says she suffered at Mayer's hands.

There's a big nod to Garland being a gay icon embodied by the couple of devoted fans who's flat she ends up visiting for a night of drinking, dancing, music and talking – as well as referring to one of Judy's real life touchstones it also conveys how crushingly lonely she seems to ultimately be, fully aware most of her life is populated by hangers on waiting for their pound of flesh.

Zellweger, who suffered a severe blow to her career years back when she completely changed her face with plastic surgery, roars back with a real performance, and however much elements of the real story are combined, coloured or maximised to convey what screenwriter Tom Edge or original playwright Peter Quilter thought was important, you feel like you're seeing an authentic slice of entertainment industry history.