Joan Rivers is a comic force of nature, and this no-bull documentary offers a profanely hilarious peek into the 75th year of her life, on the road and off. Fasten your seat belts. The idea of Rivers slowing down is not something this so-called "piece of work" subscribes to. Co-directors Ricki Stern and Annie Sundberg, best known for their doc on Darfur genocide (The Devil Came on Horseback), insert flashbacks into the high and low points of a turbulent career, including her feud with Johnny Carson, the suicide of her producer husband, Edgar, and her desire to work until she or her plastic surgeon drops. At home – in a posh Manhattan apartment Marie Antoinette would have lived in, Rivers says, "if she had money" — the comic shows us her copious files of jokes for any occasion and a support staff she financially supports in return.

Though the movie presents Rivers working clubs, trying out a play about her life in London, hawking goods on QVC and winning a tough season on Donald Trump's Celebrity Apprentice, Rivers is perpetually on the hustle for her next gig. Despite her unshakable bond with daughter Melissa and grandson Cooper, Rivers allows us to see the loneliness that seeps in around the edges of her life. As ever, she laughs it off. Self-pity is a no-no. For those who know Rivers only from her red-carpet interviews, this doc will be a revelation.

Rivers is more than a pioneering funny lady who paved the way for the likes of Kathy Griffin and Sarah Silverman. Her wit cuts as sharp as one of her diamonds, her observations as acute and timely as those of Jon Stewart and Sacha Baron Cohen. Rivers' renegade spirit animates this movie. There's not a timid, sympathy-begging minute in it. Even better, you leave Joan Rivers: A Piece of Work with the exhilarating feeling that the lady is just hitting her stride.

“Time to Pretend”

Listening to MGMT’s breakthrough song, one might interpret it as being about the excesses of rock stardom, but it’s actually about the duo’s pet praying mantis. Ben Goldwasser and Andrew VanWyngarden told Rolling Stone they got the idea from the insect's jerky movements. The mantis died, but the two bandmates kept the egg sack and allowed the hundreds of eggs to hatch. “We tried to name them all, but they died after a day,” said Goldwasser, with VanWyngarden chiming in, “But the praying mantis dance inspired us.”