The last man standing in Peter Weiss’ play is the Marquis de Sade, and for the Classical Theatre of Harlem’s brawny, caged Marat/Sade he’s played with ghoulish elegance by T. Ryder Smith (Thom Paine). Today, Sade’s acerbic, nihilistic rationale may be the French Revolution’s most recognizable voice, but we also recall Jean-Paul Marat—the Revolutionary ideologue in the iconic portrait, slumped in the bath with swathed head and a death grip on his assassin’s note.

CTH presents the first major production of the Tony Award-winning play in 40 years, and they get at the show like they were making up for lost time. Crisp, lurid leads and a trimmed text keep the political philosophy hot and lean as the projecting stage fills and empties with four-dozen Charenton asylum inmates and guards—Sade’s intimates during his final decade. When off-stage, the nutcases lurk in fenced wings at the audience’s backs, scaling and rattling the dividing metal into an industrial soundscape punctuating Richard Peaslee’s songs (piped through a tinny loudspeaker). If CTH got only one thing right, it would be Marat/Sade’s sound: soliloquies underpinned by humming loonies; Charlotte Corday (Dana Watkins) dragging the fatal stiletto along the fence; scenes of mayhem that brim the auditorium into a pitched sonic frenzy killed by shrill whistles and blasts from a crowd-control hose.

But director Christopher McElroen gets plenty right, including a wily, bell-ringing herald (Eric Walton) and Rajendra Ramoon Maharaj and Denise Hurd’s bevy of choreographic effect. Art with a political agenda seldom dates well, but with Marat (Nathan Hinton) extolling the good of war amid Sade’s theater of lunacy, when the word “freedom” rings out, it sounds more like Rage Against the Machine than, say, a State of the Union speech.

Through March 11. HSA Theatre, 647 St. Nicholas Ave. (at 141st St.), 212-868-4444; Wed.–Sat. 8; Sun. 3, $36.