When I learned that Dr. John passed away, I went into a state of shock. Malcolm John “Mac” Rebennack Jr. had been ill for some time and had stopped performing, but it was still hard to imagine a world without him. Mac was somehow a direct link to the essence of everything I love about New Orleans music, from Jelly Roll Morton and Louis Armstrong, through Champion Jack Dupree, Professor Longhair, James Booker and Allen Toussaint, and I can’t wrap my head around ...