Garth Brooks has added Denver as the latest stop on his 2026 Blame It All On My Roots arena tour, continuing the rollout of a tour that celebrates the country superstar’s return to the venues that helped launch his career three decades ago. Brooks will perform back-to-back concerts at Ball Arena on Sept. 4 and 5, making Denver the second city announced after the tour’s Indianapolis kickoff. The shows are part of Brooks’ self-described “retro are…