In the new documentary “Joan Rivers- A Piece of Work,” we see her disappointment at that call and her heartbreak after her husband’s suicide. And though she’s past 75, she doesn’t believe in calling it quits. She has no problem taking flights at 3 a.m. to get to a gig. What makes the film great is Rivers’ brute honesty and jaw-dropping humor.

“Once a Jew, always a Jew,” she quips, before making sure she has some supplies to clean her dressing room bathroom, before using it. There’s some great footage of Rivers when she first broke out on the scene, and there’s the famous clip where Carson says she’s going to be a big star.

The title, which refers to work, could also refer to plastic surgery. Rivers, whose appearance is widely mocked, is the butt of jokes at a television roast, part of which is shown in the film. In fact, the film opens with a close-up of Rivers with no makeup, and if to let the audience now that they’ll get to see the real Joan Rivers. Rivers has a great determination and a sense of self-awareness. It’s interesting to see that jokes that were risqué back in the day, which are now quite tame.

We see drawers of jokes on index cards. Some jokes are about her sex life. Others are about a wide range of topics. The film also shows her work on a show that she hoped she would be able to bring to Broadway.

The film is hilarious, with several knee-slappers. And you’ll want to wait through the end credits for a few scenes where Rivers jokes about death. Directors Ricki Stern and Annie Sundberg manage one of the best documentaries in a long time.

It’s one of the rare films that can make your cry from laughter and cry from sadness. They sift through the old and newer footage, and give each enough time so that we get a taste of enough of it without it being overwhelming or focusing too much on any one aspect.

And you’ll want to root for Rivers, a charismatic dynamo, who believes there’s no reason to throw in the towel. Comedy isn’t an easy business, we see, especially when she considers firing her long term manager, who she says is impossible to reach in rough times. One are where the film could have been better would be a few more seconds of Rivers ripping into poker player Annie Duke, because those moments are golden. It also would have been nice to hear some more words of praise from a few other comedians. It is also great to see a few seconds of Don Rickles’ praise for Rivers.

When she does a gig in Wisconsin, she’s asked if that’s the most remote place she’s performed. She tells them it isn’t. But the best moment of the film is when she turns the tables on a heckler, who tells her a joke about deafness isn’t funny.

Rivers is arguably the best Jewish comedienne of all time. This film does her justice and is a must-see. There’s wit, there’s grit and it’s a hit. In time when we are mourning stars who have passed, this film helps celebrate one that has not.

“Joan Rivers- A Piece of Work.”

Directed by Ricki Stern and Anne Sundberg

Starring Joan Rivers

Running Time: 1 hour, 24 minutes

Rated: R

Grade: A