The original plan for this article had been to use the occasion of the opening of the new, long-awaited NWA biopic to celebrate the generally improving state of films about music. For years, Hollywood has given us a view of the music business almost entirely made up of clichés and gross over-simplifications, where plucky, earnest, striving artists struggle to overcome the mendacious manipulations of The Man, and where commerce is always the enemy of creativity. But in the last few years, a number of films have shown a music industry much more like the one that really exists, where the good/bad, positive/negative dualities aren't anywhere near so clear: where artists can often be money-obsessed and malleable, and where managers, producers and label bosses might sometimes be the ones with the heroic character traits. Films that feel, even if they're not pretending to be anything other than fiction, as if they're showing us something a bit more like the truth.

But then I saw Straight Outta Compton, and the plan changed.

F Gary Gray's film, made with the co-operation of two of the surviving band members and the widow of a third, was always going to be the authorised version of one of pop's most contentious stories. But there was reason to believe - given the calibre of the individuals involved and the way that, over the years, they've hardly run shy of controversy, showing a cussed but often commendable inability to play the game and to make their art more palatable for a mainstream audience - that the version of the NWA story Dr Dre, Ice Cube and Gray would choose to tell would be one that took the good and the bad and showed them as necessary parts of the complicated and problematic whole. Unfortunately, and to the detriment not just to the film but to the way its audience will henceforth see and respond to its creators, they've not done anything like that.

To be fair, the Ice Cube we see in the film - played by Cube's son, who looks a lot more like his dad in the later stages of the story after Film Cube shaves his head - is the Ice Cube those of us who grew up with his records and films have come to feel we know, at least to the extent we feel we can know him at all. The whipsmart lyricist is talented, intelligent and often very funny - yet at the same time is shown as being occasionally indolent and roundly self-absorbed. He comes across, to use the cricketing metaphor, as something of a flat-track bully: someone who's at his best when the conditions favour him, who can take an opponent to pieces when everything's going his way, but who struggles to respond with wit or skill or poise when facing more worthy challenges. A scene in the film where Cube, flanked by Lench Mob members, smashes up his label boss's office with a baseball bat, is a case in point: we don't get a chance to really understand why he felt aggrieved because the film neglects to explain the nature of the disagreement that provoked the incident (a preceding scene suggests Cube hasn't been paid an advance he believes had previously been agreed, but never really makes clear whether it's due, it's disputed, or it's just late - each possible outcome recasting the subsequent attack as motivated by principled objections or childish impatience). Instead we just get to see a scene which makes an impact in a narrative thread that was petering out of interest, but in terms of character development it's a non-sequitur - an outpouring of directionless rage from someone who appears, whether temporarily or reverting to a well-hidden default setting, to have no ability to argue his own interests in any more constructive way.

There are manifold problems, too, in the way that NWA manager Jerry Heller is portrayed, not least in scenes featuring only him and NWA's founder member and driving force, the late Eazy-E. For reasons they've not seen fit to explain, the filmmakers put screenwriters Andrea Berloff and Jonathan Herman in touch with most of the people who feature in the film who are still alive, but specifically omitted Heller. Instead, the writers borrowed extensively from Heller's 2006 autobiography, Ruthless: A Memoir, which is therefore presumably the sole documented (if unverifiable) source for the scenes in which only Heller and Eazy appear. While the film generally shows Heller siding with his younger black clients against police racism and brutality, rendering him a not entirely negative character in the narrative, the charges made against him over the years by Cube and Dre - of unspecified claims of financial improprieties, and insinuations of skewed contracts - stand unopposed. In real life, Heller has robustly denied all such allegations, rebutting them in far more detail than the claimants have ever publicly explained them. The film comes down on the side of Heller's accusers without offering anything approaching evidence: the infamous incident at a gig in Phoenix where Cube turns down a cheque for $75,000 and refuses to sign a contract that would have turned the band into a legal entity for the first time is an exercise in smoke and mirrors - the audience presented with what looks vaguely like a convincing account but which falls apart the minute you tug at part of it. (Heller's argument - that $75,000 was by no means the totality of what Cube was owed by that point, but was a fair accounting of his share of how much money had actually come in, given the music industry's standard practices of advances paid against royalties that accrue over time, and the habit of shops accounting months after sales are logged to distributors who in turn pay labels months after receipt - is never made in a way that the viewer is intended to grasp.)

But the biggest problem the film presents is its treatment of Dre. It's not just that Gray and the writers have chosen to omit any mention of his acknowledged and, belatedly and unspecifically but uncontrovertibly confirmed, status as a serial woman-beater - it's the way they've made subtle but significant changes to the reality of the stories the film does show that appear calculated to bolster his credentials as an all-round nice guy who always stands up for what's right, even if it gets him in to trouble. At the media screening tQ attended in London the film was preceded by an ad for Dre's new Compton album, featuring Eminem, Kendrick Lamar and others; the closing track from Compton - the faux confessional 'Talking To My Diary', in which Dre's current ghostwriter is unable to come up with anything specific so resorts to reminiscences so vapid as to give even nostalgia a bad name - plays over the film's end credits; the closing image of the film is Dre taking his leave of Suge Knight, walking away from his master tapes and his millions on a point of principle, declaring that his new label will be called Aftermath (which has released that Compton album, of course); and between the last scene and the end credits there's a montage intended to bring the story up to date, in which we are given the discovery and rise of Eminem and 50 Cent, and Dre's sale of the Beats headphone range to Apple for untold millions of dollars. The ultimate effect is to turn the whole of Straight Outta Compton into a two-and-a-half-hour advertisement for Brand Dre, and to say it leaves one with a sour taste in the mouth is putting it mildly.

Gray's claim, that the beatings of Tairrie B, Michel'le and Dee Barnes were a "side story" that the filmmakers chose to leave out so as to relay a crisper narrative, is risible and offensive. (And lest we forget: while early versions of the script included the Barnes assault, there's no indication the scene was actually filmed - the part of Barnes was never cast - so the removal of this "side story" wouldn't have impacted on the running time. Gray appears to be defending the poor decision by deflecting attention on to an irrelevance.)

But let's pretend Gray's claim isn't contemptible, and just examine it at face value. Is there evidence that other "side stories" were similarly ignored to help spare the viewer the reputed extra hour the first cut took? Not really. If we assume that the job all concerned felt they were trying to do was to tell the story of NWA from roughly the time the group assembled up to Eazy-E's death in 1995, then there's plenty of stuff included in the film that also qualifies as a "side story". The career of 2Pac, for instance, is irrelevant to this narrative, yet he appears in one scene, for no other reason than to enable the soundtrack to include 'California Love' and to remind viewers that Dre produced that song too. You could argue that the story needs Snoop to be in it, because without Snoop there'd have been no Death Row-establishing, multi-million-dollar-making The Chronic: yet the two scenes Snoop appears in are there solely to allow 'Deep Cover' and 'Nuthin' But A 'G' Thang' to get played, confirming Dre as a genius because he believed in Snoop despite it being easier for him in terms of his relationship with Knight not to (the enmity between Knight, a Blood, and Crip Snoop is played up in the first scene). Moreover, the release, success and impact of The Chronic is dealt with in a couple of lines of asides in dialogue and a single scene showing multiple billboards on Sunset Strip displaying ads for the record - it's almost given the status of "side story" in itself.

The film takes significant liberties with even the parts of its source material that other people were around to witness, but sometimes there are decent reasons to do so. It can be argued that the way it handles the band's arrest after ignoring an instruction from Detroit police not to play 'F--- Tha Police' during a gig in the city makes better dramatic sense than what really happened: the group are shown fleeing the venue after police try to storm the stage midway through the song, but are surrounded by the exit and roughly bundled into a van. In real life, the gig was over and the band were all back at the hotel before the police arrested them, and that would have been a pretty dull story to tell on film.

But the way Dre is portrayed throughout has nothing to do with building drama or keeping an audience entertained. The parts where the story diverges from the known facts appear carefully and deliberately calculated to portray him in as the story's one true hero. Early on we see him arrested after rushing to the aid of his brother, who's being attacked in the car park of a night club. Eazy turns up the next day to bail him out, and the pair hatch the plan that will lead, first, to the creation of the Ruthless label, and ultimately to NWA. In reality, Dre's brief incarceration was because he had failed to pay repeated demands for around $500 in costs accrued when his car was stolen and later impounded - his legendary inability to stay on top of paperwork apparently something he never did manage to get over (in his book, Heller talks of going round to help Dre deal with some financial problem or other and finding a stack of uncashed cheques shoved into a drawer; Dre even jokes on the new LP about having Eminem royalties he still hasn't bothered to pay in to the bank). This revision sets up Dre as a braveheart whose only real fault is to be too quick to rush to the aid of his friends and family, and probably got the writers out of a bit of a hole by giving them the one scene in the film where Dre's devotion to his brother is shown (and without which, the depth of his desolation later, after his brother's death, would make little narrative sense. It's almost as if this part of Dre's life has been downgraded to "side story" status too).

According to the film, Dre apparently improvises his line in the first verse of '...'G' Thang' first take, slinging it in alongside Snoop's similarly off-the-top-of-the-head yet word-perfect lines as the two are carried away by the magnificence of the beat Dre has just thrown together in the living room of his opulent mansion. The only surprise is that Cliff Richard doesn't knock on the door and suggest that the guys do the show right here. (And, yes, I know it's trainspottery nitpicking, but the same scene wants to make us believe that Dre wrote the keyboard line on that song - we're shown him trying, failing and retrying different ideas over the top of the beat before hitting the one we recognise from the record just as Snoop ambles in to shot and kicks off his verse. Yet that line is included in the same Leon Hayward record that the rest of the track is sampled from - OK, on the Hayward track it's played by strings, not an analogue synth: but to try to suggest Dre wrote it is ridiculous. And if that's not what the scene is trying to say, then it's suggesting he's a far poorer musician than legend generally claims - so poor that he can't remember a melody from a record he already knows well enough to reconstruct from samples, even while it's playing on a loop. Whichever way you look at it, this scene is among the most laughably trite in the entire history of music-on-film, biopics or indeed, quite possibly of cinema itself.)

By the time we see Dre standing defiant and alone against a room full of drunken, gun-toting gangbangers, some with slavering pitbulls, staring down Knight in front of his goon squad and telling him to stop torturing an unnamed man who has had the apparent misfortune to come from New York and visit the Death Row studio, we're unable to know what we're watching. Did this event - or one like it - actually happen? It seems unlikely that someone who takes 25 years to own up to beating women (and then does so through a written statement supplied to a single news outlet, who still doesn't actually apologise to his victims, or even address any of the specifics), who withdrew from previously confirmed media commitments after Dee Barnes' account of his attack on her and the effect it's had on her life since was published, to have ever had sufficient reserves of backbone. But anything's possible.

Yet even if the decision not to show the beatings of Tairrie, Michel'le or Barnes was the correct one - and Barnes herself has written that she agrees with it not being shown, arguing it would be too real and too ugly for mainstream cinema audiences - the way Dre's relationships with women are depicted in the film leans so completely over to one side as to suggest everyone involved in the film was working while horizontal. As NWA indulge in orgies on the road, Dre is the sensitive one, taking a girl back to his hotel room for some loverman one-on-one time. Later, he ignores the acres of bare flesh gyrating poolside at an Eazy-thrown party to make a beeline for a woman who's caught his eye, who he proceeds to charm and, the film later shows us, date. When she tells him she's worried about moving in with him because she fears for the safety of her son if Dre remains involved in business with Knight, you're supposed to feel his anguish as his path to true love is thwarted by forces outside his control: this is presumably part of the Dre character's "journey" that ends with him severing his ties to the same thug he was so keen to use to extricate himself (with menaces) from the contract he willingly signed with his friend, Eazy-E - so, clearly, not his fault at all. (And if you think that sentence doesn't make any sense, just try watching the film.)

But worst of all is an early scene where an indolent teenage Dre has missed a job interview because he can't help but immerse himself in music. His mum points out that music will never make him a living - ho ho ho, the viewer is clearly at this point thinking; she got that one wrong, eh?! - and then, when he gives her some back-talk, she slaps him. So, in a film which ignores the beatings Dre dished out to women that are matters of documented historical fact, we get to see Dre being hit by a woman in a scene that may have happened, but might have been made up. How are we supposed to interpret that? The only possible explanation for its inclusion is as a not-so-subtle, staggeringly self-serving, and utterly offensive, attempt at justification for the violence most audience members will know Dre later went on to perpetrate against women. He was misunderstood; he only lashed out at women because his mum hit him. If it's meant to say something else, then it's inept - if it means what it appears to mean, it's indefensible.

If you can somehow manage to ignore the numerous attempts to sanctify Dre - and, believe me, I tried - there are parts of Straight Outta Compton that are pretty good. But there are nowhere near enough of them to redeem or even partly balance out the film's wilful narcissistic blindness. A sequence where Dre coaxes a reluctant Eazy into becoming a rapper is golden: here you get a brief glimpse of one aspect of why Dre might have become such a highly regarded producer. Production isn't just about tooling a sound or perfecting the technical aspects of a recording - it's about getting under the skin of a musician and helping them bring out a performance that's worth capturing on tape. And before that encounter with his mother, in the first scene where we see Dre, he's lying on his bedroom floor, surrounded by albums, Roy Ayers blasting through a pair of (no opportunity for prefiguring the brand's destiny left unexplored!) headphones, while the teenage DJ and would-be producer is lost in the sound, conducting different parts of the arrangement, pointing out nuances and emphases. Here there's a hint that NWA weren't just a bunch of blokes who struck it lucky: fortune had to favour them, but there was talent and skill there in a raw and uncut form, and without their peculiarities and peccadilloes, none of what followed could ever have happened. A few more scenes like this - actually, more than a few; maybe another couple of dozen - and we'd have had a film worth watching.

The lack of more of this kind of material is all the more unfortunate, because as well as sensing that there was enough of a sketch of an interesting film in here before it was assigned the role of facilitator for a new trunk road for the Brand Dre financial juggernaut to hurtle down, the film has been left behind by developments elsewhere. The idea for an NWA biopic has been in the works since 2009, and perhaps something this simplistic would have worked back then. But Hollywood has moved on, and there are far better films about music being made today: this means that its failings were always going to be brutally exposed.

Take Get On Up, last year's James Brown biopic. It's by no means a perfect film, yet it nevertheless found time in its 139 minutes to get in to Brown's violence against women. This was no "side story" for director Tate Taylor or writers Jez and John-Henry Butterworth, despite their film attempting to tell pretty much the whole of Brown's 73-year life story, itself every bit as culture-shaking and life-changing as anything NWA ever could lay claim to.

An even more unavoidable contrast with Straight Outta Compton is provided by Bill Pohlad's Brian Wilson biopic Love & Mercy, the other LA-set music film to make it to wide-ish release in the UK this summer. You have to feel for Paul Giamatti, who does his best with cartoon-villain roles in both films. He is marginally better as Jerry Heller than as Eugene Landy, but only because Heller has been written with a modicum of sympathy as far as his support for NWA against racism is concerned; in Love & Mercy, Landy has no redeeming features at all. But what the film does quite brilliantly, and for extended periods, is to try to show us mere mortals what it's like when magic happens in the recording studio, or inside the heads of master musicians. Its depiction of Wilson as a kind of helpless conduit between the sounds he heard in his head and the outside world, with the studio and the session musicians he employed the tools he used to get them out, is captivating, believable, relatable and entirely wonderful. Tapes of the sessions for Pet Sounds, capturing the banter and back-and-forth between the control room and the live room, have clearly been used extensively and to considerable advantage: crucially, this is one film where the availability of verifiable historical documentation has helped rather than hindered the making of the movie. The sequence showing the creation of 'Good Vibrations' sets a new high water mark for musical history on film - one Straight Outta Compton appears to have never even considered thinking about reaching.

Four other films arrived last year which dealt with different aspects of the music world: each was fictional, but they all feel like they contain more "truth" than Straight Outta Compton. Each is available on DVD, and presumably on on-demand and download services, and would represent much better value both for the money and the time required to see Straight Outta Compton in a cinema.

The reviews and box-office for Begin Again damned an excellent film with some fairly faint praise. In the UK, the current status of Kiera Knightley as being someone it's become de rigueur to decry probably didn't help - nor, when it comes to the still stereotypically sniffy music press, did the involvement of both James Corden and Adam Levine on screen, and Gregg Alexander as the writer of the numerous original songs in the soundtrack. But for the first time in your correspondent's memory, a film manages to show more of the real music business and how it actually works than any other similar endeavour in the 25-plus years I've spent time in or around it. Before last year, the films that seemed to present a believable version of how the music business operates were Almost Famous and This Is Spinal Tap - at last we have some new touchstones.

If the business worked in the way fiction frequently suggests - with noble yet naive creators routinely being ripped off by evil managers and crooked business executives - nobody would ever make a living. The crooks would be found out and either get locked up or see the number of artists willing to work with them reduce to a trickle of the least talented and most desperate. But perhaps a bigger myth is the idea that everyone in the music business - apart from the musicians - adds nothing to the end product (unless it's to dilute its authenticity or temper its rawness).

Begin Again does deal in the occasional lumpen cliché. There's a character played by Yasiin Bey, a former artist who now runs a label, who behaves as cynically and as mendaciously as any record-biz caricature. But the working relationship between Mark Ruffalo's washed-up producer, Dan Mulligan, and Knightley's singer-songwriter Greta James, is a shining example of how the creative process actually works. There's a wonderful scene towards the start, where Greta, reluctantly persuaded to perform a song at a half-empty open-mic night in a basement bar, is stumbling her way through an awkward confessional piece. Nobody's taking much notice: conversations are going on between people sat at the tables. Over in the background, a drunken Mulligan lolls across the bar top, almost passing out. But something in the song sparks him halfway towards life, and he starts to take an interest - and for the next couple of minutes we don't hear Greta fumbling over missed chords or the halting delivery of words she's still not sure constitute a finished song: Mulligan is hearing what the song could be, with a drummer, a bass player, some strings added. In other hands, with a different story to tell, this could have been the preamble to one of those old stories of commercialisation, compromise and exploitation, as the pure vision of the artist gets twisted by the money-minded suits - but writer-director John Carney has something better and more truthful to talk about. So what rises from this ashen performance is both the song Greta hopes she's written, and more than that - Mulligan's experience and ear for arrangement amplify the best of Greta's writing and performance without taking away any of the things that give it meaning and life and purpose. Throughout the remainder of the film, these themes - that collaboration does not equal compromise, and that most people you meet in the music business are involved because they actually love music and want to make more of the stuff that they themselves would pay to listen to - remain constants. The story is a fiction but the tale it tells is all the more real.

The Coen brothers' low-key take on the Greenwich Village folk scene of the early 1960s, Inside Llewyn Davis, seemed to get a bit lost in the early 2014 awards-season rush. That's a pity because Oscar Isaac's Davis is a compelling allegorical figure (though based in part on Dave Van Ronk, the Coens said that the character is a fiction), and not just for what must have been the dozens of would-be Dylans left trailing in the wake of that one icon that bent the rest of the decade to his will. This isn't a film about music so much as one about ambition and the pain that comes from carrying it, and it was criticised by some who feel that the artists of the real folk scene of the early '60s were a lot more supportive and a lot less competitive than the fictional characters it depicts. But it succeeds in telling a story that feels true despite its details being facsimiles.

Llewyn is preoccupied by not selling out: so too are many who surround the titular subject of Frank. Although co-writer Jon Ronson based elements of the plot - not least the giant papier-mâché head - on his friend and former bandmate, the late Chris Sievey (aka Frank Sidebottom), this is no biopic. Instead, Ronson, screenwriter Peter Straughan and director Lenny Abrahamson tell a tragi-comic tale of determination, individuality and mental illness. Verite is provided by ensuring that all the people playing instruments on screen could actually play them - to the extent that Frank's band (including Autolux drummer and some-time Jack White collaborator, Carla Azar) spent three weeks rehearsing as a band before starting to make the film. The story told is almost the opposite of Begin Again's tale of using music as a means of roping and drawing down hope; Frank (Michael Fassbender) is almost afraid of the success that his bandmates exist in deliberate opposition to achieving, so the music they make is as alarming and alienating as possible. That is, until an impossibly moving moment towards the end where the studied cool and the fragility it masks are hitched to a riff with the life force of a herd of elephants and the group's music becomes transcendent. It's a very different kind of magic to the one we see Wilson conjure in Love & Mercy or which Greta and Mulligan conceive in Begin Again, but it's every bit as spellbinding. Frank perhaps doesn't set out to do it in the same way as the other films discussed here, but, gently and with real emotional power, it is just as convincing in its depiction of what music means to those who make it and those it touches.

The same desire to make the musical scenes believable meant that Miles Teller spent months learning how to play drums ahead of his appearance in Whiplash. While it's entirely understandable that the plaudits the film won tended to be lobbed in the direction of his co-star, J K Simmons, it's a pity that Teller's work got overlooked. If it's the roles that require actors to slim down or beef up that get them noticed, then it would be a travesty if the ones where they have to learn or hone a complicated and difficult skill - and succeed in carrying it off with such aplomb and apparent ease - did not also count for something more than just the satisfaction of knowing that they'd played a vital part in a great movie. Still: the thing with Whiplash is that, inevitably, it's not really a film about drumming - though anyone who's ever played second violin or third recorder in a school orchestra will recognise the depiction of blind terror when the conductor halts a rehearsal in mid-flow to enquire which idiot just played a bum note. Simmons' portrayal of the tyrannical Fletcher certainly goes far further than anyone would get away with in an educational establishment in the real world - but that isn't really the point. What Damien Chazelle's film asks us to consider is the cost of achieving greatness. If you don't come away from the film with renewed respect for the musicians you revere then you need to watch it again. Its fiction serves to illuminate a greater truth: that whether or not that price is one worth paying, the individual has to find a way of making peace with the decision to pay it and the manner in which the cost was met.

These examples lead us to an inevitable conclusion: that Straight Outta Compton would have been a far better film if its makers had tried to make it fictional in whole, rather than in part. Certainly the makers of a couple of the better hip hop "biopics" - 8 Mile and Get Rich Or Die Tryin' - both thought as much. Ironically, both films starred Dre protégés in thinly veiled versions of their real autobiographies: but by making them Rabbit and Marcus rather than Eminem and 50 Cent, Curtis Hanson and Jim Sheridan gave themselves a great deal more freedom to make a compelling piece of art that said more of value about the real story it was based on than F Gary Gray has managed to do with his supposedly "real" subject matter. Notorious, the Biggie film by George Tillman, Jr., fared less well, in part because of its evident struggle with the same issues any authorised version of a controversial story will have - particularly when the producers include the late subject's mother and his record-label boss, both of whom are portrayed on screen. Life is complicated and messy and open-ended and it doesn't always cleave to the three-act structure: if we want films that feel resolved, we will probably always need them to be fictions. The truth is never so clear.

Never mind the disingenuousness that clouds its treatment of a key protagonist, the biggest problem with Straight Outta Compton is that nobody seems to be in charge. It's a film made for a series of only partially aligned motives, by people pulling in briefly similar but ultimately different directions. You sense that Cube wanted a film that conveyed something of the craziness and the warts-and-all dualities that made the group so consistently and concurrently magnetically attractive and repulsive; that Eazy's widow wanted to rehabilitate him from the servile former gang-banger turned stooge of big bad Jerry (an image wrought mostly, it has to be said, by Cube and Dre, in 'No Vaseline' and 'Dre Day'); that Dre simply wanted to look like butter wouldn't melt; and that Gray didn't ultimately feel he had the authority or the seniority to say "no" to any of them. In the end he appears to have tried to accommodate them all, to the detriment of all.

Worse, the film risks perpetuating myths and reinforcing the negative aspects of a legacy that was always at best troubling. The film attempts to highlight the way NWA's existence brought the alarming realities of life in gang-torn Los Angeles to international attention, and suggests that the group were partly responsible for helping break down the wall of lies that protected racist cops and encouraged the powerful and the politicians to ignore the truth. Gray appears to think that telling this story excuses all other errors of judgement, apparently arguing to one interviewer that violence against women is less important than violence against blacks by police.

The idea that NWA will be remembered for their highlighting of the gang war epidemic and their opposition to police brutality is unarguable, but to present it without also looking at the bullshit that came as part of the package is unjustifiable. Already we're seeing posts on social media and on comment threads beneath stories about Dre's female victims that show the effect the film is having: because those incidents don't appear in it, misogynists and trolls are berating the victims as opportunist and saying they've made up the stories to attract publicity (something Dre's risible and unspecific "apology" issued to the New York Times does nothing to address; indeed, by leaving unclear what he's actually apologising for, it gives those idiots more ammunition). The film is providing a means for the reprehensible to give themselves an excuse for saying, thinking and doing the inexcusable.

In the London screening I attended last week, the reaction to one scene above all others seemed to tell the whole sorry story on its own. There's an orgy going down in a series of hotel rooms after an NWA gig in the late 1980s. Two armed men start banging on doors: one of their girlfriends is inside, sharing an intimate moment with Eazy and about 18 other people. The NWA crew break out their own stash of (much larger, fnarr) guns, and chase the two men away. The girlfriend, wearing only a pair of knickers, is locked in the hotel corridor by a dismissive Cube, as apparent payback for her part in having spoiled the group's fun. According to Gray, the scene was improvised by Cube Jr, and was a means to include a line that implies a reference to the film Real-Cube went on to write and star in a few years later. The woman is called Felicia, so when Film-Cube locks her out, he does so by saying "Bye, Felicia" - a phrase from Friday that became an internet meme. Gray - not for the first time calling his taste and decision-making into question - has defended the scene as "a fun moment" and suggested that it represents one of the biggest laughs and better jokes in the film. It certainly had that effect at the screening in London, with about a third of the crowd breaking into guffaws. Perhaps an invited audience of media and film/music-industry people skews the response: maybe they're more likely to pick up the reference and want to broadcast that they're in on the joke to anyone sitting nearby. Or maybe most audiences will have a large component who will find the idea of a nearly naked woman being humiliated by a group of armed men to be genuinely amusing. NWA were billed as "the world's most dangerous group", and while the guns and the confrontations with cops seemed to give that tag line some legitimacy, it always sounded like an exaggeration designed to help sell records. But if their lasting legacy is to be the band whose biopic condones and legitimises abuse of the powerless, maybe the hype had some truth after all.

Straight Outta Compton is in UK cinemas from Friday. Tairrie B's new album, Vintage Curses, is available as a pay-what-you-like (or free) download. She is currently working on a memoir, as is Dee Barnes. Michel'le, too, has a book in preparation: she continues to record and perform