CAMBRIDGE — In 1968, before Lenny Kosnowski knocked on Laverne and Shirley’s basement apartment door; before David St. Hubbins turned it up to 11 with Spinal Tap; before “A Mighty Wind” was broken by the Folksmen, Michael McKean made his professional debut on the stage at the Loeb Drama Center.
“It was the first time I got paid. Actual money. To act,” recalls the actor with a smile. That year he played Troilus in “Troilus and Cressida” and The Envoy in “The Balcony.”
Now, 45 years and one wildly free-ranging career later, McKean has returned to Brattle Street to play J. Edgar Hoover to Bryan Cranston’s LBJ in the historical drama “All the Way.”
McKean had the advantage of seeing the world premiere of the show at the Oregon Shakespeare Festival last year, so it was an easy yes. (In a show where many of the actors double up, McKean also plays Senator Robert Byrd.)
“I like the idea of playing someone in history,” says Mc-Kean, whose career has taken him from sitcoms to the big screen to Broadway to national tours with Spinal Tap. “But, of course, you’ve got to start from square one.”
He’s excited to share the journey with Cranston. “I’m such a fan of ‘Breaking Bad,’ and he’s a remarkable actor. He’s one of those guys who is all in, 100 percent.”
That commitment to the work is a trait that McKean shares, says Harry Connick Jr., who costarred with McKean in “The Pajama Game” on Broadway. “It’s a religion, it’s a science, it’s an art form,” says Connick of how he observed Mc-Kean approach his role. “It was amazing. He is so brilliant: a great actor, a great performer, a great singer. He’s a very complex guy.”
As was Hoover, with whom McKean actually does have some experience, sort of.
“I was in a musical about Hoover written by Harry Shearer and Tom Leopold called ‘J. Edgar!’ It was a very disrespectful, very funny, very gay musical with Kelsey Grammer as Hoover and John Goodman as Clyde Tolson.”
Did it help him to prepare for “All the Way”? “It’s of no use at all,” he says with a laugh.
Portraying Hoover has been a challenge, he says, because the famously private director of the FBI “didn’t sit down with Dick Cavett for an interview. We only heard him carefully prepared.”
But the show does explore his notorious secret files and harassment of individuals such as Martin Luther King Jr.
“No evil person ever got up in the morning and looked in the mirror and said, ‘How can I be really evil today?’ Everyone follows what they think is the right path,” McKean says. “I worked with Helen Mirren in a film one time, and she played this really awful woman. And she said, ‘Whenever I have to play someone who I despise, I always look for what was done to this person to make them that way.’ ”