Where there is trouble, you will find Copacabana bouncer Tony “Lip” nearby.

Viggo Mortensen brings the self-made and swarthy Italian New Yorker to life in the way he carries his body, dangles a smoke from the side of his mouth and throws a punch.

Mortensen's paunch, the brill-creamed hair and the white singlet and boxers add realistic detail.

Tony is a man with a moral code: He rebuffs the Mafia mobsters who try to recruit him as a fixer and seeks a straight-laced job to support his wife, Dolores (Linda Cardellini), and their two boys.

But it’s 1962 America and Tony is not immune to the times.

He’s a racist, particularly towards African-Americans.

Worse still, he justifies his attitudes with ignorance as a member of the minority Italian community facing its own challenges in an America on the cusp of social change.

When The Copa suddenly closes its doors for renovations, Tony is out on the street and looking for work.

Meanwhile, a man seemingly caught in a lonely limbo between two worlds – African-American piano virtuoso Dr Don Shirley – is seeking secure passage to the deep south in order to perform with his musical trio.

Tony is repeatedly recommended as the ideal man for the job.

Mahershala Ali (of House of Cards and Moonlight fame) expertly conveys Dr Shirley’s pride, fear and awkward humanity.

Ali brings an emotional depth to Dr Shirley that is heartfelt, dynamic and powerful.

When the two men meet in Dr Shirley’s studio apartment above Carnegie Hall, it is as if worlds collide.

Dr Shirley is highly educated and haughty, clad in a flowing cloak and trained as a concert pianist in Europe before forging a career as a touring musician.

Tony is so comfortable in his own skin, it has become a shield of armour that prevents him from engaging too deeply with the world around him.

The film catalogues the pair’s unusual relationship on the road across the southern states of the US.

It depicts a United States that is deeply intolerant of African-American people.

Entrenched racism is so pervasive that Tony must navigate using the “Green Book” travel guide, which details the hotels and diners where African-American people are welcome.

Even as white audiences pay to see Dr Shirley perform, the venues and houses he performs at may refuse to serve him, or banish him outside to use a bathroom, for the colour of his skin.

Dr Shirley is a lonely and tortured figure, despite his outwardly dapper appearance, his virtuosity as a musician and his commitment to being agent of social change.

One of the most powerful moments in the film juxtaposes a be-suited Dr Shirley as he is waited on by his driver, Tony, on a stretch of road in full view of a gang of African-American farm workers.

The picking gang watches in disbelief as Dr Shirley, in his resplendent clothes, leans against a Cadillac while a white man pops the bonnet.

Meanwhile, Dr Shirley struggles to find common ground with the African-American people he encounters at hotels and motels throughout the south.

While he moves within the world of white America and appears outwardly to be an African-American man, he is not truly welcome - or comfortable - in either community.

This is a beautiful movie that powerfully tells the story of an enduring friendship between two men.

It is based on a true story and was brought to life by Tony’s son, Nick Vallelonga, Brian Hayes Curry and director Peter Farrelly (There’s Something About Mary) based on a series of tapes and original letters.

It has, however, been criticised by Dr Shirley’s family for its portrayal of the musician.

They argue they were not consulted in the development of the screenplay and that the two men weren’t close friends as depicted in the film.

Despite this controversy (which sits uncomfortably as a film billed as a true story) and some “white-washing” heavy-handedness in the script, I think this film will be a crowd-pleaser and possibly an Oscar contender (if nominations are anything to go by).

It is also incredibly funny, and the entire cinema was in tears throughout my showing.

Green Book is a film about courage, pride and friendship and although it lacks the overwhelming power of Spike Lee’s BlackkKlansman, it should not be missed.