Born under polemical punches, the Directors’ Fortnight was launched at the Cannes Film Festival in 1969, a year after the festival was forced to shut down amid the sweeping public protests of May 1968 — not to mention the fury of New Wave figures such as Jean-Luc Godard and François Truffaut, who saw the hoopla of Cannes as irrelevant to the aesthetic guts of filmmaking.

Thus, the Fortnight, which still runs concurrently with Cannes 40 years later, was conceived in part as a noncompetitive showcase for new directors on the cusp of something big. Spike Lee and Jim Jarmusch both “broke” here. And careers as peculiar and original as Nagisa Oshima’s and Rainer Werner Fassbinder’s ignited here as well.

During the next two weeks, BAMcinématek will survey some of the greatest hits of the mini-festival’s 40-year history. The parade includes art-house staples such as Fassbinder’s “Fox and His Friends,” Mr. Oshima’s “Death by Hanging,” and Jacques Rivette’s eternally winsome and endlessly adored “Céline and Julie Go Boating,” which kicks off the series tonight in a new print courtesy of the British Film Institute.

But, in an effort to illuminate the Fortnight’s contemporary significance, the BAM program will also dish out a batch of premieres. These include Emmanuel Mouret’s “Change of Address,” a romantic comedy with affinities for vintage Woody Allen, and Claire Simon’s “On Fire,” in which a teenage crush on a heroic firefighter goes dangerously pyrotechnic.

One thing the series aims to reflect is a lack of cinematic hierarchy. The Fortnight at 40 program accommodates everything from Roger Corman’s “The Trip” — a 1967 time capsule artifact written by Jack Nicholson and starring Peter Fonda as a television commercial director who spends a hard day’s night on his first LSD trip — to Béla Tarr’s “Werckmeister Harmonies,” which saturates the viewer in trancelike perceptions instilled by 15-minute takes.

“We are very curious, looking for all kinds of films,” the artistic director of the Fortnight, Olivier Père, said. “But we have some solid ideas about what is a good film or not. It protects us from fake discoveries or impostors.”

It also attunes the selections to films that otherwise were ignored by cultural gatekeepers. Mr. Père, a critic and, since 1995, a staffer of the Cinémathèque Française, mentioned the 2006 entry “12:08 East of Bucharest.” The satire, about the collapse of the Ceausescu regime in Romania, is one of the central films in that country’s new prominence in world cinema.

“It was rejected by all the selection committees in Cannes except Directors’ Fortnight, and it won the Camera D’or,” he said. Mr. Père also mentioned the Spanish director Albert Serra, whose work is not being screened at BAM. Mr. Serra made his Fortnight debut in 2006 with “Honor de Cavalleria,” a radical, poetic retelling of “Don Quixote.”

“It became an underground hit and a cult movie after its presentation at the Fortnight,” Mr. Père said. After the film’s success, its follow-up, “Birdsong,” was invited to the 2008 Fortnight, though even then there were no givens. “I thought that nobody would invite his film to a festival because you may think it was too crazy, too wild, or too experimental.”

Of course, anything so deemed no longer requires a festival platform, or even mainstream distribution, to find an audience. It’s remarkably easy to go online and find the most obscure and wigged-out movies from anywhere in the world and download them. How does the connoisseurship of the Fortnight continue to matter as digital culture so instantly connects filmmakers with audiences?

“We matter because we are a very selective festival,” Mr. Père said of the Fortnight, which screens 22 features each year. “And we want to present not only the best films, but surprising and uncompromising voices among the new international auteurs and directors.”

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