With this ‘To Kill a Mockingbird,’ a classic remains a classic

Richard Thomas as Atticus Finch in "To Kill a Mockingbird."Julieta Cervantes

What a truly remarkable vehicle the young and unknown Harper Lee constructed all those years ago when she wrote “To Kill a Mockingbird.”

After all, how many works of fiction have hit the artistic trifecta the way “Mockingbird” has, succeeding as a novel, then a film, and now a stage drama by Aaron Sorkin? Precious few.

In Bartlett Sher’s outstanding production — now at Citizens Bank Opera House, kicking off the play’s North American tour and starring a superb Richard Thomas as defense attorney Atticus Finch — the built-in strengths of Lee’s sturdy and supple work transcend the playwright’s impulse to Sorkin-ize any story.

He’s known for scripts with a words-per-minute velocity that sets land speed records, and when it comes to tolerating Sorkin’s style, your mileage may vary. Inevitably, there are times in this “Mockingbird” when people say clever things because Sorkin wants them said, whether they fit the character or not.

But he’s got many strengths of his own, among them this pertinent one: The man knows from courtroom drama.

Don’t forget that his breakthrough success was the 1989 Broadway production of “A Few Good Men” — later, of course, a movie with Tom Cruise and a fire-breathing Jack (”You can’t handle the truth!”) Nicholson. In Sorkin’s “The West Wing,” too, the clash of ideas and personalities was a central dynamic.

So he’s a dab hand at crafting entertaining scorpions-in-a-bottle showdowns, and that makes “Mockingbird” a tightly focused, fast-moving, and gripping affair.

Within the first few minutes of the play, Sorkin takes us to the courtroom in small-town Alabama where, in 1934, a Black man named Tom Robinson (a quietly moving Yaegel T. Welch) stands falsely accused of rape. That is where Atticus will mount a stirring defense of Tom, and where American racism itself will be on trial.

Sorkin puts that poisonous racism, both individual and systemic, on display in “Mockingbird,” and it’s raw, ugly, and unsparing. (Scenic designer Miriam Buether has created a spacious and versatile set that exudes a certain ominousness.) The vile Bob Ewell (Joey Collins) is clearly meant to embody the dangers of white supremacy not just then but now.

The 1962 film version of “Mockingbird” starred Gregory Peck at his Gregory Peck-iest, and when Jeff Daniels played Atticus on Broadway in 2018, he brought a trace of Peck-like stolidity to the role. Thomas’s Atticus has less of the plaster saint about him, a little less certitude to his rectitude, and that’s all to the good. It’s a portrayal as skillfully calibrated, albeit in a different key, as Thomas’s 2018 performance in Stephen Karam’s “The Humans” at the Shubert Theatre, portraying a man whose world is coming undone.

What helps make Atticus a more complex figure in this stage “Mockingbird” is the countervailing force represented by the Finches’ Black housekeeper, Calpurnia (an excellent Jacqueline Williams). Sorkin has smartly enlarged Calpurnia’s role, and she provides real-world pushback to Atticus that is grounded in the Black experience. Atticus’s brand of complacent idealism is, after all, a form of white privilege.

From left: Yaegel T. Welch, Stephen Elrod, Jacqueline Williams, and Richard Thomas in "To Kill a Mockingbird."Julieta Cervantes

His mantra is “There’s goodness in everyone”; Calpurnia points out the abundant evidence to the contrary. When Atticus says, “I believe in being respectful,” she comes back with a retort that underscores the wider stakes of that attitude: “No matter who you’re disrespecting by doing it.”

As with any Sorkin script, this kind of trenchancy is periodically marred by bursts of show-offery. Points are italicized that don’t need to be, and sometimes a figure from the Depression-era Deep South sounds suspiciously like the urbane Mr. Sorkin himself, creating not just tonal inconsistencies but contradictions of characterization. In one scene, for example, Bob Ewell tosses off the word “condescension” while accusing Atticus of elitism with implausible elaborateness; then, later, Ewell appears not to know the meaning of “ostracize.”

His 19-year-old daughter, Mayella, who makes the unjust accusation of rape against Tom Robinson, is played by Arianna Gayle Stucki. The actress builds a harrowing portrait of desperation; her Mayella is part of, yet also trapped by, pernicious forces.

As young Scout Finch, Melanie Moore expertly transitions back and forth from narrator to participant in the action. (Mary Badham, who played Scout so wonderfully in the movie, plays a small role in the play as a vituperative neighbor.) Also lending strong support are Justin Mark as Scout’s brother, Jem, and Steven Lee Johnson as their friend Dill, though Sorkin devotes a bit too much stage time to the latter, especially in a scene that dissipates the tension from a preceding argument between Atticus and Calpurnia.

Those, after all, are the two we need to hear from, along with Tom Robinson. And one other: Six decades later, we still need to hear the voice of Harper Lee. Changes and all, this “To Kill a Mockingbird” lets us do that.

TO KILL A MOCKINGBIRD

Play by Aaron Sorkin. Based on a novel by Harper Lee. Directed by Bartlett Sher. Presented by Broadway In Boston. At Citizens Bank Opera House. Through April 17. Tickets start at $44.50. www.BroadwayInBoston.com