Bradley Foster Smith in “Picasso at the Lapin Agile.” (C. Stanley Photography)

His canvases may still be selling for a relative pittance, but the Pablo Picasso who shows up at a Parisian bar in 1904 is making a killing on personality. As zestily portrayed by Matthew J. Keenan in Keegan Theatre’s “Picasso at the Lapin Agile,” the Spanish-born artist is a disheveled, swaggering womanizer who talks in ranting tones, because he’s so pleased with his own opinions. Don’t mention any potential rivals in his presence; the future Cubist goes into a scowling funk when he even hears the name Matisse.

Keenan’s Picasso and Bradley Foster Smith’s brightly kooky Albert Einstein are the spark plugs of this generally amusing, if occasionally stagey, production, directed by Chris Stezin from a loose, jokey script by Steve Martin. Among his many credits — actor, comedian, banjo player, co-creator of the musical “Bright Star” (recently seen at the Kennedy Center and upcoming on Broadway) — Martin is a noted art connoisseur, and he knew what he was about when he set this play in 1904, just three years before Picasso produced his seminal painting “Les Demoiselles d’Avignon.”

In 1904, Einstein was only on the verge of publishing the theories that would revolutionize physics. So part of the breezy, sometimes absurdist humor of “Picasso at the Lapin Agile” stems from the idea of glimpsing luminaries in their early days, before they had become the household names they are today. Underappreciated at the Lapin Agile (a real historic establishment in Paris), the 25-year-old Einstein of Martin’s play is at one point casually roped in to helping amiable bar owner Freddy (Brandon McCoy) with his bookkeeping.

Also patronizing Freddy’s drinking spot are the opinionated art dealer Sagot (Lee Liebeskind), the aging barfly Gaston (Kevin Adams) and the beautiful Suzanne (Amanda Forstrom), who has recently succumbed to Picasso’s philandering. ( “. . . The word ‘No’ became like a Polish village . . . unpronounceable,” she says, in one of the script’s characteristic gags. “I held out for seconds.”) And then there’s the flamboyant self-promoter Charles Dabernow Schmendiman (Michael Innocenti), who may or may not become world-famous for inventing a building material made out of asbestos, radium and kittens’ paws. (Erin Nugent designed the costumes.)

Souped up with the occasional easygoing intellectual-history insight, the comedy washes around on a roomy barroom set, with giant stylized scraps of scrawled-on paper floating overhead, to evoke the throes of genius. (Cast member Keenan also designed the set.) The actors sometimes move around this space with a deliberateness that looks very choreographed. And a couple of the performances in the production are more serviceable than inspired.

Bradley Foster Smith and Lee Liebeskind in “Picasso at the Lapin Agile.” (C. Stanley Photography)

But it’s fun to watch Smith’s Einstein, who looks like a silent-comedy star and often brims with glee over insights or jokes that only he can understand. And Keenan’s egomaniacal Picasso is a delight. How does the Lapin Agile manage to attract such prodigies? There must be something in the absinthe.

Wren is a freelance writer.

Picasso at the Lapin Agile

By Steve Martin. Directed by Chris Stezin. Lighting design, G. Ryan Smith; sound, Tony Angelini; projection design, Patrick Lord; set dressing and properties, Carol H. Baker; assistant director, Sheri S. Herren; hair and makeup, Craig Miller. With Allison Leigh Corke, Sheri S. Herren, Jessica Power, Mike Kozemchak, Katie Rosenberg and Caroline Leffert. About 85 minutes. Tickets: $30-$40. Through Feb. 13 at the Andrew Keegan Theatre, 1742 Church St. NW. Call 202-265-3767 or visit keegantheatre.com.