In the pantheon of "thons," few excite us more than Madonnathons (just pythons and Toyotathons, really). Last night, in honor of Madge's 49th birthday, hundreds of her craziest fans converged on B.B. King Blues Club to enjoy semi-reverent live performances of her greatest hits by amateurs professionals of various genders, both talented and non. Vulture's Elizabeth Cline and Jonah Green were on hand.