Torch Song Trilogy is a movie that evolved from a smash-hit Broadway show, which in its turn, evolved from three off-Broadway plays centred around the life of Arnold Beckoff, a gay, Jewish drag-queen in pre-AIDS New York.

Arnold is played by the writer of the pieces, Harvey Fierstein, and as the movie opens, we see him at his worst – in tight closeup, he talks to us about his life as a homosexual, in a deep gravelly voice, as he transforms his clearly male features into a parody of a female torch singer. He seems open, honest, and vulnerable, then suddenly he pushes us away again with a sarcastic one-liner.

This is how he protects himself – and he does need to protect himself. He falls in love often, he never does it by halves, and sadly he isn’t always wise about who he chooses to fall for – so he gets hurt.

The film divides into three sections, based on the three individual plays. In the first, The International Stud, Arnold meets and falls for Ed (Brian Kerwin). It’s a big thing for Arnold – the biggest ever -- so he jumps out of bed in the morning, rushes to the bathroom and makes himself as gorgeous as he can, before slipping back beside the sleeping Ed, just as the alarm goes off.

Unfortunately, although he’s made all the running, Ed isn’t quite so sure – he’s bi-sexual, exploring his sexuality, and finally, inevitably, he decides to plough a straight furrow. He leaves Arnold, who is devastated, to go and marry.

In part two, Fugue in a Nursery, Arnold is alone again, and on stage at the club where he works. There are a rowdy group of hecklers in the audience, amongst them, Alan, a gorgeous young fashion model (Matthew Broderick) The group make a mockery of Arnold’s set, and afterwards, Alan seeks him out to apologise. Arnold is off-hand, but Alan is fascinated. He starts a determined pursuit, under which Arnold’s resistance gradually crumbles. The scene in which he finally agrees to go out with Alan is a camp classic – the drag queens are in a gown shop, trying on costumes to the horror of the assistant, and as Arnold relents, his ravaged face peering out over the changing room doors at Alan’s flawlessness as he says "Okay, but if anyone asks, I’m the pretty one!"

It’s a great relationship, solid. The couple even go up to visit Ed, and his wife Laurel at their farm. This is uncomfortable for everyone but Alan, who, unbeknownst to Laurel and Arnold, seduces Ed – a small revenge for his treatment of Arnold, sowing seeds of doubt in the bi-sexual man’s mind about his decision.

Alan and Arnold return to New York, and begin to set up house together, buying a place in a low rent neighbourhood, and being selected to adopt a gay teenager. Everything is perfect as they move into their dream home – and then Alan goes to help an old man who is being set upon in the street and is beaten to death. It isn’t even really a gay-bashing, just a stupid, tragic happening.

This time, though, Arnold isn’t alone – he has his adopted son, David to consider. The final part Widows and Children First takes up the story a year after Alan’s death. Arnold is struggling to deal with his depression and loneliness, and to keep a handle on a troublesome teenager. Ed has left Laurel and is sleeping on the couch at Arnold’s and Arnold’s mother, who has never really come to terms with her son’s homosexuality, is due in town for a visit. She doesn’t know about Ed, and she doesn’t know about David, so there’s already tension in the air.

David is supposed to make himself scarce, so that Arnold can break the news gently, but instead, he wades in and announces himself to his "grandmother", and things blow apart. The climax of this section comes in a harsh confrontation between Arnold and his mother in a graveyard, where he tries to make her understand the scope of his loss by comparing it to her widowhood. She is disgusted and horrified that he can compare his “unnatural” and shortlived affair with Alan to her long, legitimate marriage, and they part, bitterly.

As the story winds down, tempers have cooled, and a tenuous understanding is reached between mother and son -- not perfect, but liveable – there is a possibility of the relationship with Ed moving back to more than friends, and Arnold and David have recognised what they mean to each other – it is a cautiously hopeful conclusion.

Now all this makes the movie sound heavy and highly dramatic – in fact, it is achingly funny too. Feirstein’s wit is never swamped, and just as he’s wrung a horrified tear, he’ll send you into hysterics with an aside like “Well, with a voice like this, I can always be a taxi driver”. There is irony in the way his own mannerisms with his son mirror his mother’s with him. There’s no shortage of puns (A drag queen called Bertha Vanation is Arnold’s closest friend) and some of the visual humour is just perfect – the scene where Arnold is called to the school to deal with David’s behaviour and stalks down the corridor dressed in a housecoat with pink bunny-ear slippers slapping aggressively along the floor will reduce you to howls of laughter.

It would be a serious mistake to write this film off as a "Gay Movie". It’s about people, mistakes, misunderstandings and relationships. And it’s marvellous.