Far from feeling outdated, The Rocky Horror Picture Show is more relevant now than ever. Released on Aug. 15, 1975, Richard O'Brien's musical is about rock 'n' roll, transgressive sexuality and the way those two go hand-in-hand.

It all came to life in London in 1973 as the brainchild of O'Brien, a stage actor who loved sci-fi B-movies, '50s music and glam rock. He showed his script to Australian director Jim Sharman, who put the play on in several locations before securing the King's Road Theater, where The Rocky Horror Picture Show enjoyed a six-year run.

By 1975, the play was a hit in America as well, and there was enough momentum to make a film. Sharman and O'Brien decided that the movie would feature mostly British stage actors who had been in the play, including Tim Curry, but the film's producers insisted that two of the leads be played by Americans, so Susan Sarandon and Barry Bostwick were hired.

The story opens with a young couple, Janet Weiss (Sarandon) and Brad Majors (Bostwick) deciding to get engaged after attending a wedding. Delighted with their decision, they attempt to drive to the house of an old mentor, a scientist named Dr. Scott, but get a flat tire and end up instead at the castle of one Dr. Frank-n-Furter (Curry).

Watch the Trailer for 'Rocky Horror Picture Show'

Turns out, Frank (as he's called in the film) is not merely a scientist; he's also a "sweet transvestite from transsexual Transylvania." His castle is home to drag shows, guests who look like they wandered in from the set of Cabaret, and a retro sci-fi laboratory where Frank has just finished constructing a hunky blond creation named Rocky (Peter Hinwood).

The uptight Janet and Brad are initially shocked by the proceedings, but are both soon overcome by the atmosphere and give in to Frank's advances. When other members of Frank's retinue grow jealous of his dalliances, he finds himself forced to use a "Medusa Transducer" to turn them all into marble statues. He then dresses the statues of Janet, Brad, Rocky, and Dr. Scott in drag and brings them back to life, whereupon they help him perform a sprawling musical number featuring a swimming pool and a mock-up of the tower and lighting bolts from the old production logo of RKO Pictures, famous for its monster films of the 1940s and '50s.

The Rocky Horror Picture Show ends when two of Frank's associates, Riff Raff (O'Brien) and Magenta (Patricia Quinn) reveal that they, along with Frank, are actually aliens from the planet Transsexual in the galaxy of Transylvania. Disappointed with the way Frank has acted here on Earth, they kill him and then blast the castle off into space, leaving behind a shell-shocked Janet, Brad and Dr. Scott.

Watch the 'Sweet Transvestite' Scene from 'Rocky Horror Picture Show'

All of this is accompanied by musical numbers, numerous references to the sci-fi films O'Brien loved, and other strange touches. The opening credits feature a pair of red lips singing a song that references everything from Flash Gordon to Claude Raines' role in The Invisible Man, and in the final musical number Rocky carries Frank up the mock RKO tower in a visual gloss on King Kong.

Meat Loaf makes an appearance as an ex-delivery boy who has had half his brain donated to Rocky, and the opening scene (in which Curry also appears as a dour-looking minister) features a pair of actors dressed up like the couple in the famous painting "American Gothic."

The main undercurrent of the film, however, is sexuality. Rocky Horror trains its ironic sights on traditional sexual mores early on. At the end of the wedding that opens the film, the bride and groom drive away in a car on which has been painted, "Wait 'till tonight: she got hers, now he'll get his."

Watch the 'Dammit Janet' Scene from 'Rocky Horror Picture Show'

Janet and Brad are the incarnation of this kind of approach toward nuptials: pale, square, and positively askance at any hint of debauchery. They transform into sexually liberated creatures throughout the film, of course, and this flowering is matched with a new sympathy for Frank. Initially seeing him as a menacing figure, they (and we) come to pity him as he is killed in the end by his own compatriots for simply wanting to be himself.

The Rocky Horror Picture Show reflected society’s sexual awakening, with the wholesome couple representing the ‘50s while the transexual doctor and his half-naked cohorts were the ‘60s.

The film's creator says the plot goes back to one of the oldest stories in history. “It’s a retelling of one of the oldest root fairytales in the world – Genesis, Adam and Eve,” O’Brien later told the BBC. “Brad and Janet are Adam and Eve and the serpent is Frank-n-Furter.”

Rocky Horror did poorly on its initial release in the United States, but almost immediately became a cult sensation. Within months of its appearance in theaters, the film was moved to midnight showings, and soon audiences began dressing like the characters and performing the roles in front of the screen – sometimes reciting the lines and often talking back to the characters.

Watch the 'Time Warp' Scene from 'Rocky Horror Picture Show'

These celebrations of the movie have never ceased, as The Rocky Horror Picture Show mounted the longest continual run in history: The film is still in limited release, as it has been since 1975.

That longevity underscores the project's influence, but also similarities between the moment when the it was made and our current one. The Rocky Horror Picture Show helped crystallize the on-screen impact of pop music and rock 'n' roll – particularly glam rock – and its in-your-face style influenced directors like Baz Lurhmann as well as inspiring modern works like Hedwig and the Angry Inch and Transparent. Beyond that, however, Rocky Horror was one of the first mainstream depictions of cross-dressing and alternative sexuality, bringing what had previously been viewed as taboo subcultures to mainstream audiences.

This is helped by the performances – Curry and Bostwick in particular are fantastic – but also by the fact that the film's misbehavior is directly in line with the tradition of the music that serves as its backdrop. Rock 'n' roll has always been about desire, about things like dressing in a way that identifies you as an adherent (from your tee shirt to your hair cut) and about participating in rituals (from hippie-dancing to moshing) that might seem strange to the uninitiated but for devotees are about pure expression.

The Rocky Horror Picture Show simply took that tradition, pushed it a bit further, adding in elements of sci-fi and camp, and put it on the screen. As any midnight moviegoer will tell you, it's still a recipe that works.


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