Police said the gunman, identified as Ian David Long, opened fired inside the country-western. It was the deadliest mass shooting since 17 students and teachers were killed at a Parkland, Florida, It even set the opening lineup to the song ‘This is Me’ from The Greatest Showman, performed by the soul singer Leela James. Performers will include Jenny Slate, David Spade, Nicole Byer, and Sal V. I can understand when…