PLASTIC SURGERY. Celebrity Apprentice. A screeching red-carpet harpy, stalking celebrities with mic in hand. Joan Rivers has worked in show business for more than 40 years, and her comedic pedigree is undeniable, but even today she's more concerned with drawing a paycheck than preserving her legacy. Rivers' persona has come to overshadow her accomplishments—the result of years spent trying to reconstruct her face into relevance and shilling for any product that'll pay her.

The filmmakers behind the new documentary Joan Rivers: A Piece of Work don't shrink from acknowledging Rivers' image, but they also provide some valuable context: Rivers was a groundbreaking female comedian, mentored by Johnny Carson, who for years guest-hosted The Tonight Show and continues to tour and perform tirelessly. She's a 77-year-old performer in an industry that places a premium on youth and beauty, a workaholic who isn't happy unless the pages of her day planner are inked solid.

Though she insists that her first love is acting—that she is, in fact, an actress playing the role of a comedian—Rivers' comedic chops are well documented here. Whether she's performing at a celeb-studded tribute to George Carlin or swatting down a heckler in the Midwest, Rivers is damn good at what she does.

The filmmakers spent 14 months trailing Rivers at a time when her main focus was producing a play about her life that she hoped would bring her back into the public spotlight. It should come as no terrible surprise that while the one-woman show failed to capture the public imagination, her victory on Donald Trump's reality TV show Celebrity Apprentice launched her back into the spotlight. But Rivers is better than the company she kept there, a klatch of semi-stars milking reality TV's self-perpetuating cycle of fame. Joan Rivers: A Piece of Work gives Rivers' life and work a deserved re-contextualization, a reminder that behind the diva shenanigans and synthetic face is a performer who's legitimately influential, pioneering, and above all, pretty damn funny.