NEW YORK (AP) - A new posthumous album of previously unreleased Michael Jackson music comes out May 13.Epic Records and the late pop singer's estate will release Xscape, an album of eight new tracks that have been updated musically by producers including Timbaland, Rodney Jerkins, Stargate, Jerome Jroc Harmon and John McClain.Executive producer L.A. Reid refers to the work as contemporizing