Michael Sparks has a particular affinity with the book To Kill A Mockingbird. Like his character, Atticus Finch, in Canberra Rep's production of the stage adaptation by Christopher Sergel, he is from a small town in Alabama.

There were, he says, a number of similarities between Lee's fictional Maycomb of the 1930s and his home town of Anniston, Alabama.

When Sparks was growing up in the 1960s and '70s, Anniston was a small town of about 20,000 with a mixed-race population and some hostilities between black and white citizens.

"I grew up during the integration of schools, a time when the tension was highest," he says.

"Before I was born one of the Freedom Riders buses was burned in my hometown."

He says he felt like he knew the people in the book when he read it in high school, such as the gossiping ladies and the sheriff - "all typical characters you'd see in a small town - they all had them".

There was even a mysterious recluse who was seldom seen in public and about whom wild stories spread - "We always thought he was stalking us" - like the story's Boo Radley (Cameron Thomas).

Sparks's great-great-uncle Chauncy Sparks was a lawyer and politician who served in the Alabama state legislature at the same time as Lee's father, Amasa Coleman Lee, a journalist and lawyer as well as a politician,  who inspired the character of Atticus.

Chauncy Sparks was not progressive, he says, unlike the older Lee, a writer and lawyer as well as politician who represented, unsuccessfully, a black father and son accused of murder.

That event was changed in the book - and the 1962 film as well as the play - into Atticus being assigned by the court the difficult and controversial defence of Tom Robinson (Jack Tinga), a black man accused of raping a white woman.

Atticus doesn't relish the thought and is concerned about the effect the case will have on his son Jem (Jamie Boyd) and his daughter Scout (Jade Breen) who, along with their friend Dill (Jake Keen), have more than one life-changing experience during the course of the story.

Sergel wrote his play long before the Aaron Sorkin adaptation now playing on Broadway. The former uses the device of having one of the Finchs' neighbours, the sympathetic Miss Maudie Atkinson (Antonia Kitzel) as the narrator, providing the audience with a direct link to Maycomb and its people.

Sparks says the Atticus of the book seemed a bit more human and in the play more nuanced and prone to ill-temper, "not all quiet charm and control" like Gregory Peck's Oscar-winning cinematic portrayal.

He sees the theatrical and literary Atticus as someone who is a decent man rather than a really progressive hero in a political sense.

As for why a play based on an American novel published in 1960 is still relevant, Sparks says the issues of race and equality are still real in Australia now, applying to Indigenous people, migrants and others.

"The other thing the play is really about is loss of innocence - that's always going to be relevant."

That's obviously applicable to the children - who, guided by Atticus, begin to see what happens in Maycomb in new ways as they grow up and have different experiences.

But Sparks says it's true to an extent of Atticus too, who is confronted when his disbelief about how bad people can be receives a shocking rebuttal.

Still, Atticus tries to instil good values in his children, providing an example through his own conduct and guiding them in life through advice and direction, such as as showing them what he says true courage is.