The summer series opens Wednesday, June 19, with a special celebration of Juneteenth featuring Brian Blade & The Fellowship Band (note two separate shows at 6:00 p.m. and 8:30 p.m.). One of the world’s leading jazz drummers, Blade brings Jon Cowherd on piano, Melvin Butler on tenor and soprano saxophone, Myron Walden on alto saxophone and bass clarinet, and Roland Guerin on bass, to the Athenaeum for their first local appearance.