Red-hot controversy erupted when I Am Curious (Yellow) opened 29 years ago.

Curiosity killed more than the cat. When the sexually explicit Swedish romp I Am Curious (Yellow) entered the country via New York’s Kennedy Airport in December 1967, the U.S. Customs Service immediately confiscated it on grounds of obscenity. For over a year, Curious would be in legal limbo before opening in New York City, March 10, 1969 — and fanning the flames of a racy new era in Hollywood.

”If you’re speculating with sex and have nothing to say artistically, you’re going to have a bad film,” said director Vilgot Sjöman, an Ingmar Bergman protégé, apropos of his comedy. ”But if you have something to say, you’re on safe ground.”

What Sjoman had to say, however, seemed to depend on your point of view. The approximately $160,000 film, shot in six months without a script, follows ”Lena,” a young woman who experiments with politics, religion, social mores —and, of course, sex, with ample nudity and sex scenes ensuing. The U.S. government considered it pornography. The film’s distributor, Grove Press — whose founder, Barney Rosset, had also sponsored the first American editions of Tropic of Cancer and Lady Chatterley’s Lover in the 1950s and ’60s — considered it art, and Rosset made a spirited defense of the film before a federal jury, but Curious was still ruled obscene in 1968. However, thanks to the testimony of such witnesses as writer Norman Mailer, who called it ”one of the most important pictures I have ever seen,” a U.S. Court of Appeals overturned the decision later that year; within months, the film opened in Manhattan. Though it drew protests in Philadelphia, Cleveland, Denver, and Detroit, was closed down in Boston, and was banned outright in Baltimore, Curious was eventually shown in more than 53 cities, grossing a then-staggering $5.2 million in its first six months, with the two New York venues alone accounting for almost $1.3 million.

In the wake of Curious, graphic sex entered this country’s cinematic consciousness in such films as 1969’s Midnight Cowboy and 1970’s Myra Breckinridge. But in the last decade especially, mainstream American films returned to comparative modesty; unsparing sex scenes are once more the province of peripheral films like NC-17 progenitor Henry & June and last year’s Boogie Nights. After all these years of sexual revolution on and off screen, almost nobody, it seems, is curious anymore.