Midway through opening night of the Celebrating David Bowie tour at London’s Brixton Academy on January 8th, guitarist Earl Slick, who played on everything from Diamond Dogs , in 1974, to The Next Day , in 2013, found himself so overcome with emotion he struggled to keep playing. He was backing Def Leppard’s Joe Elliott on “All the Young Dudes” alongside a 20-piece gospel choir, Spiders From Mars keyboardist Mike Garson and the rest of the group assembled for the 2003-04 Reality tour, but images of Bowie, who would have turned 70 that day, kept flashing through the guitarist’s head.