Curious experience, this Megalopolis. Francis Ford Coppola’s 40th directorial effort has the antiqued flavor of a valedictory mega-production—especially given its opening night live-action streaming introduction featuring Coppola, Robert De Niro and Spike Lee on the big screen, from the New York Film Festival. But the 138-minute costumed extravaganza, written by Coppola and produced under the banner of his American Zoetrope, has more than just “farewell” on its mind.  There’s so much happening onscreen it would take a three-hour “making of” to examine it all.  Megalopolis may appear sloppy at first glance, but “ferociously busy” better describes the hectic allegorical tale of the fictional city of New Rome and its jousting, utterly ingrown ruling class.  The movie has one or two problems. Argentine composer Osvaldo Golijov’s bombastic musical score often gets in its own way, as influential architect/fashion designer Cesar Catilina (Adam Driver) contends with corrupt Mayor Franklyn Cicero (Giancarlo Esposito) and decadent billionaire Hamilton Crassus III (Jon Voight), all struggling for power in a framework borrowed from several far-fetched sources. In tone and narrative thrust, their urban clash echoes Ancient Rome in the days when Julius Caesar’s republic gave way to the imperial cupidity that eventually turned that civilization into a Gothic Nowheresville. Combine that historical thread with Fellini-esque situations and characters (Satyricon, anyone?), mouthing their forced-sounding proto-Shakespearean lines in a lobcockled “futuristic” setting. Megalopolis flutters through its Western Civ refresher course in a restless flurry. Unfortunately the hurry-up makes better story sense in retrospect than it does in the hot moment. When the characters go into voiceover narration it only reinforces the artificiality. Pinnacles of visual virtuosity—courtesy of Romanian cinematographer Mihai Malaimare Jr.—occur every few minutes as the camera investigates the sinister carnival of thievery and murder. After a while we don’t even notice. The future has never looked so outdated. Driver’s Catilina is in love with Julia Cicero (British actor Nathalie Emmanuel), daughter of the mayor. When they’re together, nuzzling in bed or posing together precariously on top of a skyscraper, Julia exudes a warm, sensuous fragility. By comparison, her boyfriend looks as if he’d rather be somewhere else. It is Driver’s misfortune to wear the movie’s most outlandish hairstyle, although Dustin Hoffman, in a cameo as somebody called Nush “The Fixer” Berman, runs a close second.  As often happens in this type of saga, the subplot is more entertaining than the main event. Jon Voight’s super-rich Crassus is named after the original “crass” mogul of Ancient Rome, General Marcus Licinius Crassus. He and his family provide the greed and sleaze that make New Rome instantly relatable. The plutocrat’s grandson Clodio Pulcher (Shia LaBeouf), a power-seeking rich kid of the type familiar to 21st-century audiences, is fond of showing up at large public gatherings in drag. Otherwise he sneaks around with his grandfather’s mistress, Wow Platinum (played by Hollywood’s current “It Girl,” Aubrey Plaza). Clodio and Wow make a game of deceiving the old man, but Crassus is craftier than he looks. Unfortunately the film never delves as deeply into the sins of Esposito’s Mayor Cicero.  The send-up of celebrity worship gets thrown into the satirical blender along with lengthy montages of street crime, political riots and a few sexy musical numbers. A song performed by Vesta Sweetwater (Grace VanderWaal), one of the movie’s unexpected highlights, is much too attractive to be wasted in the shuffle. As if Coppola’s barbed portrait of New Rome’s unhappy residents weren’t obvious enough, the movie climaxes with its own humanistic Pledge of Allegiance. Coppola reportedly financed the production of Megalopolis himself, by selling some of his winery properties. That can-do spirit identifies him with his generation of independent-minded filmmakers from the 1960s. Megalopolis never quite finds the right rhythm for its laborious critique of timeless immorality, but 52 years after The Godfather, Coppola still finds meaning in social commentary. And Coppola’s throwaway scenes are more worth seeing than most directors’ best. * * * In theaters