Pioneer comedian. Plastic-surgery freak. Red-carpet maven. Foul-mouthed shock artist. No matter how you think of her, Joan Rivers—A Piece of Work is likely to expand your idea of who, exactly, Joan Rivers is. As the film follows her through her 75th year, Rivers fights to stay busy and relevant in a world with waning interest in her work. With startling drive—motivated at least in part by her fear of a blank appointment book—she plows through a seemingly never-ending string of projects: preparing a play based on her life, competing with her daughter on Celebrity Apprentice, pitching product on QVC, throwing an elaborate Thanksgiving in her ornate New York City apartment and eliciting both shock and laughter in a string of stand-up appearances in every imaginable kind of venue. Filmmakers Ricki Stern and Annie Sundberg make the most of their subject’s characteristic mixture of bravery and the desire to entertain, even if at her own expense. Working mostly with observational footage and interviews both funny and frank, Stern and Sundberg pepper the film with enough archival material to remind us of Rivers’ bright taboo-breaking beginnings and of the disappointments and tragedies in her life. The end result is a complex portrait of a born entertainer—a constantly shifting mixture of determination, fear, moxie and regret—who continues to persevere despite what others may think of her.