Spare, elegant, disjunctive, initially annoying and ultimately drop-dead beautiful, Marguerite Duras’s “India Song” (1975) was one of the great European art films of the post-art-film era. It followed the 1960s heyday of Michelangelo Antonioni, Ingmar Bergman and Alain Resnais, Duras’s one-time collaborator (she wrote the screenplay for his first feature, “Hiroshima, Mon Amour”), and was in some ways more radical than their work.

Like much of Duras’s work, the film, streaming through May 3 on the highly curated site, Mubi, is obliquely self-referential, drawing on earlier writings as well as her childhood in French-occupied Indochina. It originated in the early 1970s as a play — commissioned but never staged by the National Theater in London — loosely based on her 1965 novel, “The Vice-Consul,” in which a French diplomat in Lahore painfully yearns for the French ambassador’s promiscuous wife.

“India Song,” which begins with a stunning sunset, shot in what feels like real time, is nominally set in late-1930s Calcutta (but was filmed in and around a French chateau). It is less theatrical or literary than it is ritualistic and, as the title suggests, musical. A handful of characters — notably Delphine Seyrig as the ambassador’s unhappy wife and Michael Lonsdale as the smitten vice consul — languidly drift, pose and pivot around an old-fashioned drawing room.

Incense burns, the dominant color is a velvety jade green, and the single Indian servant wears a turban. (The story takes place in a bubble — you never see India or, the one servant aside, Indians.) The action is the more stylized for being scored with society jazz and for unfolding in the sultry, rarefied world of European colonialism. Intimations of madness, horror and suicide hover just outside the narrative.