Quentin Tarantino’s Once Upon a Time in Hollywood poses two questions. Can an entertaining movie be made against the backdrop of the Manson family murders? Has he found future cinematic muses in stars Brad Pitt and Leonardo DiCaprio?

The answer to the first question is a definite yes.

The answer to the second is a definite maybe.

Brad and Leo both turn in riveting performances in Tarantino’s latest opus.

As fading star Rick Dalton, Leo has the flashier role, artfully expressing Rick’s vulnerabilities through his self-obsession.

Brad is just as memorable as Rick’s stunt double Cliff Booth, his laconic self-confidence a counterbalance to Rick’s insecurities.

It seems counterintuitive to describe Once Upon a Time in Hollywood as a coming-of-age film for two middle-aged actors (Pitt is 56 in December, DiCaprio turns 45 in November), but that’s more or less where we are.

Since Brad flashed his sculpted abs to Geena Davis in Thelma & Louise (1991) and Leo smooched Claire Danes at the Capulet shindig in Romeo + Juliet (1996) both have invested time and energy into putting their youthful beauty behind them.

You’re welcome: A 28-year-old Brad Pitt becomes an instant star in Thelma & Louise. Photo: Metro-Goldwyn-Mayer

For actresses, the old Hollywood cliché dictates that the more stunning they are to look at, the more they need to get messy to be taken seriously. Accordingly, Jennifer Connelly descended into heroin addiction in Requiem For A Dream (2000) Charlize Theron stalked highways as a drifter serial killer in Monster (2003).

You’ll also remember when Once Upon a Time in Hollywood’s Margot Robbie became Oscar-nominated trailer-park trash in I, Tonya (2017).

DiCaprio and Pitt went a different way, becoming muses for Hollywood’s elite directors.

DiCaprio replaced Robert De Niro as Martin Scorsese’s default collaborator, starring in five of his movies (compared to De Niro’s eight, with a ninth – The Irishman – to premiere in September).

Pitt made three movies with thriller auteur David Fincher. For a large part these roles still relied on the actor’s physical presence as driven police detectives or street hoodlums. Apart from being punched repeatedly, their handsome faces were left alone.

Hollywood has been eager to embrace the pair as not just pretty boys. Pitt has been nominated for three acting Oscars and DiCaprio for five. But it wasn’t until Leo completely de-glamorised himself by being pulverised by a bear and sheltering in a hollowed-out horse in The Revenant (2015) that he took a gold statuette home.

Leo goes wild on a number of levels in The Revenant. Photo: 20th Century Fox

Now they both join the likes of Samuel L Jackson, Harvey Keitel, Uma Thurman, Michael Madsen, Tim Roth and Christoph Waltz as repeat Tarantino collaborators, and their access path has been trusting the director to cast against type and embrace their increased salt-and-pepper-haired cragginess.

Pitt was the gruff, uncouth, hillbilly Lieutenant Aldo Raine in Inglourious Basterds (2009).

DiCaprio brought such focused, oily malevolence to his role as slaveholder Calvin Candie in Django Unchained (2012) that he sliced his hand while filming some key dialogue, soldiering on regardless.

Both actors lead very public private lives. Early in his career Pitt emerged as a Y-chromosome version of Elizabeth Taylor, dating or marrying and divorcing a string of A-list actresses including Juliette Lewis, Gwyneth Paltrow, Jennifer Aniston and Angelina Jolie.

Jennifer Aniston and husband Pitt at the 2001 premiere of Spy Game. Photo: Getty

DiCaprio has never been so settled. A serial modeller, he is regularly snapped at secluded beaches sporting a beard and a dad-bod, with a 22-year-old clothes horse by his side.

Not even actors can dodge mortality forever.

Robert Redford now takes loveable grandpa roles formerly reserved for the likes of Wilford Brimley (see 2016’s Pete’s Dragon).

But there are other ways to leave a legacy. As Redford’s successors, Pitt and DiCaprio remain active politically with progressive causes such as environmentalism, child welfare and same-sex marriage.

So, if this is what growing old for men in Hollywood entails, where do I sign? It’s somehow fitting that a director accused by detractors of building his career on arrested male development provides the conduit for Brad and Leo’s autumnal roles.

Will they work with Tarantino again? I hope so.

In struggling to transcend the curse of being two of Hollywood’s most dashing leading men (and in Brad’s case, People magazine’s two-time Sexiest Man Alive) slumming it in LA with Tarantino looks to be just the ticket.

Of course, this requires Quentin to confirm he actually will make another film, but that’s a story for another day.