“Hello. Good evening, hello. I have cancer, how are you?” That’s the opening to Tig Notaro’s now-legendary set at Largo, which Louis CK introduces. He loved the set so much that he made it available for a limited time on his website, and now you can own it on CD or LP. To put it mildly, Notaro is struck with a series of tragedies — she gets pneumonia, which leads to a life-threatening bacterial infection, then she goes through a breakup, her mother dies tragically and she finds out she has cancer in both breasts. And while Notaro speaks with a palpable weariness, she marvelously weaves her calamities into deeply black, deeply funny comic material. Beyond the hilarious way she makes fun of her own situation, at one point saying she picked up a photo of herself as a child and told it it was going to get cancer, in one memorable bit, Notaro amazingly is able to play off of the audience’s audible sympathy, nervous laughter and silence when she enters particularly dark territory. As Louis CK put it, it’s simply masterful, and painfully funny in the truest sense.