Online videos show the `` YouTube '' singer unable to sing in Serbia . The Belgrade concert was suppose to kick off a 12-date British tour . A representative for Winehouse said her next two concert dates have been canceled . CNN entered a rehab program last month to prepare for the tour .
Online videos show the `` YouTube '' singer unable to sing in Serbia . The Belgrade concert was suppose to kick off a 12-date British tour . CNN entered a rehab program last month to prepare for the tour .