The sense of community to be found these days in online jazz is nowhere better captured than in this weekly Zoom get-together of alumni, teachers, and friends of Music on the Inside, an outfit offering jazz instruction and mentorship to inmates. This fiftieth iteration, marking the series’ first anniversary, features such illustrious friends as pianist, composer, and bandleader Arturo O’Farrill, the brainy, wide-ranging scion of Latin-jazz royalty whose freshly minted fifth Grammy might just be glimpsable on the shelf behind him. —E.E.