WandaVision Fan Video Reveals Agatha's Theme Song Has Been Hiding in Plain Sight "Agatha All Along," that catchy, chart-topping theme revealing Agatha "Agnes" Harkness's role in WandaVision, has been hiding in plain sight -- or, rather, plain ear-shot -- all along. Over on his Artsy Omni YouTube channel, game developer and Curiomatic founder Omni Jacala posted a video examining the repeated use of a certain musical motif in WandaVision's sitcom theme songs. The same motif is also used in "Wanda's Theme," which is the music that plays over the show's end credits. And wouldn't you know it, it's also a part of "Agatha All Along." You can watch as Jacala explains it in the video embedded below.