Amy Winehouse performs at Nelson Mandela birthday concert
Despite her recent health problems, the British singer Amy Winehouse has performed at Nelson Mandela birthday concert held in Hyde Park .
Amy Winehouse, whose minor 2006 hit ``Rehab'' was not at all ominous or even cheaply faux-ironic on your Twitter feed the other day, celebrated her 28th birthday September 14 by playing a small show in her native London.