Joan Rivers: 'I'm the funniest person performing stand-up today'

A couple of weeks ago, I went to see the comedy veteran Joan Rivers perform her stand-up routine at the Venetian Hotel in Las Vegas. If you are unfamiliar with Joan's work and of a delicate disposition, please look away now. If you are easily shocked or liable to take offence on behalf of famous people or ethnic minorities, read no further.

And if you happen to be under the age of 18, there's probably a law that says I should advise you to seek parental consent before viewing the contents of the forthcoming pages.

All done? Good. So, Joan's act lasts for an hour and a quarter, and mostly consists of two sorts of jokes. The first involve sweary put-downs of female celebrities, including Demi Moore ("that cunt"), Oprah Winfrey ("lesbian"), Barbra Streisand ("so fucking ugly"), Olivia Newton-John ("bitch"), Victoria Beckham ("skinny bitch") Heather Mills ("fucking bitch") and Angelina Jolie ("vagina lips"). The second take aim at special interest groups: old people, Chinese people, blind people, fat people, thin people, cripples, Jews (of which Joan is one), and Catholics. "It's so EASY being a Catholic," she observes, in a typical gag. "All you people have to do is get fucked by a priest, and they'll give you a set of candlesticks."

It's not to everyone's taste, this. But it goes down a treat among the Saturday-night crowd, even though many of them are Catholics, Jews, and/or fat people. At one point, just after Joan describes lesbians as "miserable", a female couple walks out, but for the most part her insult jokes hit the mark. As ever, she turns some of the cruellest gags on herself. "I'm so old. It's awful," goes one. "All my friends are dying. That's why I always wear black."

Rewind five days, and I'm sitting in Joan's home in Manhattan, drinking coffee poured into fine bone china by a uniformed butler called Kevin, and picking at an antique silver platter filled with her favourite M&M's (the chocolate variety, not the peanut ones). We are discussing the crude, sometimes cruel jokes which helped her achieve fame on Johnny Carson's Tonight show in 1965 and still keep her in the spotlight, in glorious defiance of the old adage that show business is supposed to be a young woman's industry.

At the height of her powers, Joan was one of the most famous women in America: sidekick to Carson, star of her own chat-show, and one of the biggest earners on the Las Vegas strip. Today, still internationally famous at 77, she remains something of a cult: young people love her as the potty-mouthed old woman who pokes fun at celebrities on E! and does reality TV. Old people like to reminisce about her glory days on prime-time. Gays adore her, just... because.

Her longevity is, in a roundabout way, the reason we're meeting. Next month, Joan will grace British TV screens in a documentary called Joan Rivers: A Piece of Work, which followed her relentless daily life for 75 days of 2008. The film won plaudits at the Sundance Festival, and subsequently made $3 million during a short American theatrical release. Critics were struck by its unflinching portrayal of her age-defying existence on the front line of entertainment; some said it has re-invigorated her career. Roger Ebert called it "one of the most truthful documentaries about show business I've seen; also maybe the funniest".

The documentary isn't all homage, though. It followed Joan everywhere ("I could barely urinate without a camera zooming in") and the resulting portrait was somewhat melancholy. It shows her to be rich, famous, right-of-centre, politically, and deserving of a place among the greatest entertainers of the modern era. But it also makes no bones about the fact that she's 77, has no husband or boyfriend, lives thousands of miles from her daughter and grandson, and spends most of her life schlepping to theatres, comedy clubs and TV studios, to earn a buck.

Ricki Stern, the director of A Piece of Work, tells me that when Joan first saw the film she complained that it was "sad" and asked, "Where are all the happy parts?". Today, she is more stoical. "People are seeing survival in it. It's about survival," she says. "They think: 'How lucky that lady Joan Rivers is: she's still working! She's 77 and she's wanted!'." Then she adds: "The film made it look like I have no private life. That's not true: I do work 92.7 per cent of the time, but the other 7.3 per cent is my time."

Either way, Joan is keen to promote the documentary because she'll take a cut of any profits. Money is one of her favourite things; indeed, her affection for it lies at the heart of many of her famous jokes, which play on her image as a stereotypical Jewish grandmother. "When my husband committed suicide," goes one such gag, which she tells in Vegas, "I had the watch and pinkie ring in my mouth before the body hit the ground". Like much of Joan's comedy, genuine darkness lies behind this one-liner: Edgar Rosenberg, who she married in 1965, took his own life in 1987.

The principal setting for A Piece of Work is Joan's New York apartment. It overlooks Central Park, and is decorated in the style of a Ferrero Rocher advert: all antiques, gilt, hand-painted murals, and expensive rugs. In the lavatory, towels are embossed with "JR", fittings involve gold and mirrors, and visitors choose between six differently-scented pink hand soaps. Joan often describes it as her own Versailles: "the sort of place Marie Antoinette would have lived in, if she'd had any money".

When you arrive, a uniformed bell-boy escorts you to the lift. Once you reach Joan's gaff, which covers the top two floors, the doors open and you are greeted first by a smell of pot-pourri and then by Kevin, who wears a white jacket. After that come two extremely noisy black lapdogs, followed by Joan's always-sunny assistant, Jocelyn. One of the pooches, a Pekingese called Max, wears a nappy to prevent him soiling the extravagant carpets.

It seems unbelievable that the creator of jokes so famously coarse should live in a place which aspires to such refinement. But juxtaposition lies at the heart of Joan's comedy. She is simultaneously coarse, and fabulous; her lifestyle is high-brow, but her punchlines belong in the gutter. When she emerges to greet me, she is made-up to the nines, and looking far younger than she has any right to (thanks, as she often reminds fans, to some of America's most expensive plastic surgeons). In fact, her bearing is positively regal.

We adjourn to a room she calls the "library", perch on sofas, and accept a delivery of miniature Danish pastries from Kevin. Joan, who watches her weight (she always carries a tin of Altoids, to suppress her appetite), nibbles at the corner of one. The Pekingese, Max, has no concerns about his waistline. She drops several pastries into his little mouth, saying, in her doggy-voice: "Life is good, isn't it? But we don't want to get too fat, do we?".

After that, it's on with the tape recorder and down to business. We start by tackling the central question posed (but never quite answered) by A Piece of Work. Why, as she approaches her ninth decade, does Joan not sit back and enjoy the fruits of her labour? Why does she still punish herself with a regime which – to take the previous few days as an example – will in a typical week see her perform live in New York and Las Vegas, fly to LA to film her TV show for E!, in which she lampoons celebrity fashions, and then spend 48 hours making a new reality show called Mother Knows Best. Her lifestyle, by anyone's standards, seems terribly gruelling. Why doesn't she just relax?

"Relax? Darling, all my friends who have relaxed are no longer in the business!" comes her reply. "You can't relax. How can you, when you never know if you're going to be asked to perform again? Sometimes, I look back on interviews from when I had my daytime TV show, see the names of the guests, and think, 'Oh my God, remember how hard it was to get that person?'. And then I go: 'Where are they now?'. Two thirds of them simply disappear. People lose interest in them. They don't decide to quit; no one decides to quit. They just disappear."

To stop herself "disappearing", Joan has decided that a straightforward philosophy should underpin her career choices: there is no performing job, however low-brow, that she won't accept... provided the price is right. One of her biggest earners these days is a range of costume jewellery she designed and helps flog on the shopping channel QVC. "I have no exclusivity, but I'm still working, so it hasn't hurt me," she says. "I could be the Greta Garbo of comedy, very secluded, but Garbo had a man who was beyond rich to support her. It's easy to be exclusive when you know you're going to have steak for dinner."

Joan often therefore ends up rubbing shoulders with C-listers on the reality show circuit. In 2008, she won America's Celebrity Apprentice. Soon afterwards, she was the subject of Comedy Central's annual "roast", in which slightly-famous comedians spend hours mercilessly insulting a public figure, before a live studio audience. This year, when the same role was taken by David Hasselhoff, they mocked his vanity and alcoholism; with Joan, the jokes were about age and plastic surgery.

Behind such fluff, it's easy to forget how genuinely groundbreaking Joan Rivers once was. Born in 1933, into a respectable Jewish family from Brooklyn, she originally wanted to be an actress, and received career advice from Marilyn Monroe, who she met at a dinner party in the 1950s. It went: "Men are stupid, and they like big tits". To this day, she regards acting as her vocation, and as shown in A Piece of Work, which follows her as she opens a play in London's West End, she can be hugely upset by less-than-ecstatic reviews of her occasional forays into theatre or film.

She began doing stand-up in New York comedy clubs in the late 1950s, to supplement her earnings as an office assistant. Realising she had some talent, Joan moved to LA to seek her fortune. When she broke into late-night television, first as a joke-writer, then an occasional performer, she was a rare female voice in a milieu dominated by men. Later, she became the first female entrusted with her own late-night network TV show. Without her groundwork, it's no exaggeration to say that we might never have seen the likes of Sandra Bernhard, Roseanne, and Sarah Silverman.

Throughout her career, Joan's craft has always been all about sharp one-liners, expertly delivered. She writes jokes constantly, scrawling them down on little cards, which she files in a vast cabinet in an office upstairs at her apartment (one drawer for jokes about "sex", another for "marriage"). "Who the hell knows how a joke works," she tells me. "Woody Allen once said to me, 'If something works, you say thank you God, and go on to the next'. There are pieces of paper all over this house, and in my purse, I jot down stuff and then work on it. But sometimes I go on the stage, and something will come out of the blue."

Lately, she's begun getting Jocelyn to test-drive gags about pop culture on Twitter. The day we met, she posted one about the current season of the hit TV show Dancing With the Stars, a US version of Strictly. "I am still so upset about @ DavidHasselhoff being the first one voted off DWTS," it read. "He was eliminated faster than Betty White's bowels."

Once a joke is written, Joan will usually practise and perfect it. Then she'll try it on an audience. If they laugh, she'll use it again. It they don't, Joan will steer her routine back to old favourites: jokes about marital sex, say, or Madonna's adopted son. She tapes every show, and sometimes gets another employee, Graham, to replay the best bits. After 50 years in the business, there's still plenty of graft behind her craft.

"I have come to the conclusion that this kind of comedy is what I do best," she says. "You know, I actually think I'm the funniest person performing stand-up today. That's humble, isn't it? But I really think I am. I'm very strong now, stronger than I ever was. It's because I have no boundaries any more. What are people going to do? Fire me? I've been fired before. Not book me? I've been out of work before. I don't care."

For inspiration, Joan reads newspapers and watches TV. One of the few headline-prone individuals that she usually lampoons is her good friend Prince Charles, whose last Christmas card still has pride of place on the table in her living room, despite the fact that it's late September. "He sends me a gift every year. You get a wonderful china teacup. After a few years you've got six with wonderful twirls on them."

Only very occasionally will she self-censor a topical gag about a public figure. She recently, for example, decided at the last minute to kill a joke about Michelle Obama's dress sense, which she was going to use on her E! show. The reason? It might be considered racist. "I was going to compare her to Jackie O, but call her Blackie O," she says. Normally, though, she has a sort of compulsion to be gratuitously offensive.

While we're on the subject of race, Joan usually subscribes to one golden rule: "Only blacks can say nigger". But other comedians she admires haven't always been so careful. "Lenny Bruce, I saw him when I was 16 and he went round the room saying, 'You're a nigger, you're a kike, you're a wop, you're a chink. Everybody's something, so who cares'. And it just levelled the playing field, so in a way, he was right."

She believes in this, in a roundabout way, saying that her craft must help people deal with sometimes difficult questions; to chortle in the face of tragedy, and flick a metaphorical V-sign at life's imperfections. "Telling jokes is how I deal with bad things," she says. "Say I was on a plane that's about to crash... I would turn around and tell my neighbour: 'If my goddam insurance isn't paid, I will kill my broker'." In a recent TV interview, she said: "I would have been laughing at Auschwitz".

Life has actually provided Joan with its fair share of tragedy. If a therapist were to analyse her steely refusal to shuffle off into retirement, they would almost certainly make two points: firstly, that like all workaholics (and many geniuses) her sense of self-worth is tied up in her professional achievements; secondly, that she's been motivated for at least some of the past 23 years by a desire to stick two fingers up at Fox, the TV network she holds responsible for her late husband's suicide.

The story behind Edgar's death is only occasionally told by Joan, but it features prominently in A Piece of Work. In 1986, when she was at the height of her fame, she was poached to launch her own late-night programme on the newly established Fox. Edgar, a Rugby-educated Englishman who was father of her only daughter, was hired to be the producer. It was called The Late Show, Starring Joan Rivers.

Although it opened to strong ratings, things did not run smoothly behind the scenes. Both Rupert Murdoch and Fox chief Barry Diller clashed with Edgar. They disliked some aspects of the show's tone, and rather more aspects of his personality and occasionally toxic manner on set. After a few months, they presented Joan with an ultimatum: fire her husband, or have the show scrapped. She took the latter option. Fox has never since allowed her to appear on its late-night schedules.

Edgar killed himself three months later, swallowing a bottle of pills. He blamed himself for the "humiliation" of the show's cancellation and left Joan not just distraught, but also in debt. His death left a gaping hole in her comedy routine, which at the time majored on jokes about marital sex. Typically, though, she ploughed right through it: when she honoured a stand-up engagement not long after his funeral, she began her routine with a gag about the personal tragedy.

"When you walk on stage and the whole audience knows your husband has just killed himself, I suggest you make a joke about it, so they can all just relax," is how she recalls that night. "The first thing I said was, 'My husband's killed himself, and according to the will, I can't get the money unless I visit him every day. So I had him cremated and got the ashes sprinkled in Neiman Marcus [the department store]'. They all laughed; then we did the show."

You can't say much, in response to an anecdote like that, apart from smiling, sipping coffee, and responding out loud that Fox's loss was the world of comedy's gain. Seconds later, the silence is broken by Jocelyn, telling me that my time is up. By way of a going-home present, I'm given a Joan Rivers watch, from the QVC collection, in a little black box.

Then, as I'm tidying away my notebook, a final thought. "You asked earlier whether I would ever retire," she says. "You know, I would rather die. In fact, I want to die onstage. I don't know if you know this, but in a comedy contract, your show is an hour and 15 minutes, and you have to work at least half of it to be paid. That makes 38 minutes. So when I do finally go, I want it to be the 39th minute of a show." That would be rather appropriate, don't you think?

Joan Rivers sounds off

'I've had so much plastic surgery, when I die they will donate my body to Tupperware'

'I blame my mother for my poor sex life. All she told me was, "the man goes on top and the woman underneath". For three years my husband and I slept in bunk-beds'

'A man can sleep around, no questions asked, but if a woman makes 19 or 20 mistakes, she's a tramp'

'Grandchildren can be fucking annoying. How many times can you go, "And the cow goes moo and the pig goes oink"?'

'I hate housework. You make the beds, you do the dishes and six months later you have to start all over again'

'Funny people are very angry people. And they turn their anger into funny'

On Paris Hilton: 'All I can think of are her poor parents. The shame, the shame of the Hilton family. To have your daughter do a porno film... in a Marriott hotel'

On her daughter Melissa: 'For a mother and daughter we're amazing. The only time she really cried is when I sat her down and told her that she was not adopted'

'Joan Rivers: A Piece of Work' premieres at Sheffield Doc/Fest on 3 November and will be broadcast on More4 on Tuesday 9 November at 10pm