SPOILER ALERT: This story mentions plot developments in Season 1, Episode 4 of “Agatha All Along,” currently streaming on Disney+. Although “Agatha All Along” isn’t a musical per se, music serves as the show’s literal plot device, when the coven led by Agatha Harkness (Kathryn Hahn) sings “The Ballad of the Witches’ Road” together in […]