It’s hard to believe that the forever-young Michael Jackson would have turned 55 this year. His death in 2009 shocked the world, and audiences still hunger to hear unreleased material from Jackson’s catalog. “Xscape” is the second posthumous compilation of unheard Michael Jackson songs. It was curated by Epic chairman L.A. Reid, and the updated production was supervised by Timbaland. Plus it features guest appearances from Justin Timberlake, Mary J. Blige, Questlove and D’Angelo. This is “Xscape,” Michael Jackson and our Album of the Week.