ANNAPOLIS — Singer-songwriter Cas Haley takes the stage at 1 p.m. on Sunday, May 16, at Rams Head On Stage in Annapolis. Sometimes when one door closes, another one opens. Haley never imagined that in the year of the pandemic, both doors would belong to a 2020 Lincoln Corsair that would take him on a musical adventure across the country. But maybe he shouldn’t have been surprised. It was just the latest soulful swerve in the musical ebb and flow of a career that’s been both full of challenges and mightily blessed.