Meshell Ndegeocello, 'Virgo' When she sings of supernovas, she sounds like a witness YouTube A few years ago, in a catalog essay for a major exhibition of the artist Jean-Michel Basquiat, critic Greg Tate cast a sidelong glance at the voguish recent turn for Afrofuturism, a creative mode that took shape on the margins before accruing its cultural and literal …