After last week's PBS documentary "Unforgivable Blackness: The Rise and Fall of Jack Johnson," there have been several calls to Graceland Cemetery, where Johnson is buried, from visitors who want to see Johnson's grave. If you go, don't pay your respects at the big headstone labelled "Johnson;" although it was his intended headstone, Jack Johnson is actually buried in an unmarked grave next to that of his first wife Etta. And if you missed the documentary when it aired last week, it'll be rebroadcast on WTTW's digital cable station, starting today. See here for a schedule.