IN THE forties, I thought, people went to movies they could believe in--in both senses. There were the old virtues to believe in: love, courage, trust, honesty. And the characters to believe in: there were villains, who fought those virtues, and heroes who exemplified them. Moral conflict was between persons, not within them, and sex was something to think about after marriage--but the movies all ended just before marriage.

Of course, times have changed, and since then Hollywood has grown up, depicting a crueler world of vice, not wickedness, and mediocrity, not evil. But when I delved back further, into the twenties and thirties, I found vice and evil too. Suddenly I discovered that adults had always been adults, and that the hidden meanings I now discovered in the forties concoctions had always been there. The world had been sophisticated before I grew up to appreciate it.

So, in The Boy Friend, when MGM heralds the "return of entertainment," there's no reason for them to fear that the film's total lack of verisimilitude will alienate today's "sophisticated" audience.

The Boy Friend--"All Singing, All Talking, All Dancing"--is just like an enormous plastic Christmas tree, thousands of gaudy decorations obscuring a very simple trunk, the girl-gets-boyfriend plot. The girl in question, Twiggy, gets the boy friend pretty much through divine right as star of the film and through no readily apparent merit of her own. As Polly Browne, understudy cum assistant stage manager of a seedy British theater, she is called out one day to replace the aging star (Glenda Jackson) who has hurt her foot in a tram accident. Remember, credibility is not the point. Just before Polly is due to go on--and face the sparse matinee audience--the moment occurs that pushes the film straight into baroque fantasy from what appeared to be a straightforward musical.

Christopher Gable, the boy friend to be, comes over to remove Twiggy's owlish spectacles. Pause. Gasp. "Why Polly!" he gulps, "You're beautiful." Beautiful she is not. She dances wonderfully; she sings the light pseudo-twenties songs with just the right lilting soprano, but her acting puts her back in the assistant stage manager position where she started. Ms. Jackson, who appears for a few short minutes as the show's erstwhile star, does not shine here as an actress either. The film belongs entirely to director Ken Russell, who has her appear leg first--sporting an enormous white cast with two red-painted toenails peeping forth. In the space of two minutes he makes her suggest the entire run of has-been stars from the first Hollywood queen ceding to the second, to Bette Davis watching Anne Baxter's rise at the other end of the see-saw in All About Eve. Russell takes several such characters and manages to make them represent more than they could ever possibly be, which accounts for the exceeding richness of this film and also the utter excruciation of those scenes which last too long. When he can say so much so well, it's a pity he can't perceive and cut those places where he says nothing.

BUT THAT'S only if you're the type of person who can be bored at a light show. The stage is always in motion, the costumes are sumptuous, the imagination runs rife. What Russell did with Glenda Jackson as a fading star, he has done also to Sandy Wilson's "The Boyfriend" as a musical. Milking the musical tradition for all it is worth, he's put the cream onto the screen.

They're all there: the lucky understudy, the reunited father and son, the aging star, the play within a play convention, the color, the team spirit, and True Love. Added to these is Mr. DeThrill, a Hollywood tycoon who for some unknown reason decides to attend a matinee in this particularly tacky town somewhere in the sticks of Britain. A new Busby Berkeley who sees in color instead of black and white, he imagines everything as it might appear on the Big Screen. Suddenly the confines of a stage are forgotten. His multiple vision transforms each girl into a bevy, each actor into a troupe, each singer into a chorus. The dancers form phalanxes and kicklines and giant grids; they pirouette into place onto giant record discs in the shape of rosettes; they turn their heads and make their paper thin headdresses vanish. And then there's the tunnel-of-legs sequence, with a long camera track at floor level passing under the opened legs of the chorus line. The film degenerates into travesty, extending the traditional fascination with bodies as clockwork. You can see just how repulsive it really is--especially when the bodies are magnified on the screen in overwhelming flesh-color.

This seamy side to the film is increasingly evident as it continues. Everyone--except for Twiggy and her boy friend--displays a singular corruptness. Actors shove their way to the front of the stage like runners in a relay race. Their troubles are all for nothing; DeThrill walks off without signing a single contract, and even virtuous Polly and her boy friend don't reach the bigtime. They, however, are simply content with what they've got. "I could be happy with you, If you could be happy with me."

BUT TWIGGY and the boy friend are the most unreal character in the film, although the tycoon, with his ubiquitous cigar, comes a close third. Christopher Gable, who plays Tchaikovsky's lover in Russell's The Music Lovers (Glenda Jackson played his wife) doesn't look much different here; it's all in his surroundings. Russell doesn't show much interest in his actors, using them more like props than people. In Women in Love, with good actors speaking a script derived from D.H. Lawrence's novel, Russell's direction added that overripeness that characterizes Lawrence's prose. But in The Music Lovers, with only Jackson to uphold the acting and an original script, Russell turned the whole project into a fruity joke. Instead of characters he shows embodied forces or traditions--and essence of sweetness-and-light is simply more bearable than essence of wife-of-a-homosexual.

This kind of cinema is rich and strange, and not too easily digestible. Ken Russell's helping unfortunately reaches a surfeit about halfway through.