Just as I was sitting down to write about Rock 'n' Roll—Tom Stoppard's 2006 play about communists and rock bands in Prague and London—a young playwright, a friend of mine who heard I was at the show, sent me a text.

"Remember, Stoppard is both our friend and our enemy," he wrote. "He knows he can get away with this play because he's written better plays. And we give him a pass because we loved Rosencrantz and Guildenstern Are Dead." The young playwright is correct (though I'm adding Arcadia to Dead). Stoppard has even written some dreadful plays, but Rock 'n' Roll isn't dreadful. It is merely good.

It begins in 1968: The Czech Republic is trying to reform its way from Soviet shackles and toward freer speech, travel, and press. The USSR freaks out, Leonid Brezhnev sends in the tanks, and young Jan flees Cambridge and Max, his British Marxist mentor, to fight for reform and "socialism with a human face." In the play's first lines, the fusty old Max (played by a delightfully crotchety Denis Arndt) excoriates Jan (Matthew Floyd Miller) for putting nationalism before the revolution. "At the first flutter of a Czech flag, you cut and run," Max growls. "Fuck off back to Prague, then. And I'm sorry about the tanks."

The play ping-pongs between Cambridge and Prague, measuring the fallout (political, professional, romantic) of 1968, with a special emphasis on popular Stoppard themes: the intersection of intellectuals and pop culture, and younger women who lust after older, professorial men. (I'm not judging, Tom. Just noticing.) Rock 'n' Roll is a fast-moving crash course in Czech history: Václav Havel, "the power of the powerless," Charter 77, the Plastic People of the Universe—a real-life band of psychedelic rockers—and whether their rock 'n' roll decadence qualifies as political dissent. "The policeman isn't frightened by dissidents!" Jan declares to a Czech friend. "Why should he be? Policemen love dissidents, like the Inquisition loved heretics. Heretics give meaning to the defenders of the faith... But the Plastics don't care at all. They're unbribable."

The play doesn't soar through the cerebral stratosphere like Arcadia and doesn't have the machine-gun wit of Dead, but ACT's quality cast gives it a rich, human glow. Anne Allgood, in particular, delivers a soul-scorching monologue as Eleanor, a professor of ancient Greek and Max's cancer-stricken wife. In the middle of an argument, Max gets carried away with his dialectical materialism. Eleanor fires back: "I don't want your 'mind,' which you can make out of beer cans. Don't bring it to my funeral—I want your grieving soul or nothing!"

She fell to the floor, and the audience applauded her in the blackout—an actor elevating a line from mere goodness to greatness.