Executive producer Mary Livanos tells Marvel.com that this was the case in the early days of development Agatha all the time, She and showrunner Jac Schaeffer knew music had to be a central part of the story. So they re-recruited the Lopezes who had worked before WandaVision.

“We were very lucky to have them and they brought their magic to the process and really gave the actors even more support,” Livanos says of the Lopezes. “The song is incredibly catchy and everyone who watches the show sings it too. I can't tell you how many times I've been stopped in the halls of Marvel and people have let me know that they just can't get it out of their head.”

To prepare, each of the actors practiced their instruments in the weeks leading up to the scene. Alice plays piano and Agatha sings lead, with Sasheer Zamata's Jennifer Kale on bass, Joe Locke's Teen on guitar, Aubrey Plaza's Rio Vidal on drums, and Patti LuPone's Lilia Calderu on triangle.

“I came home from long days of filming and thought, 'I have to practice!'” Ahn remembers. “But it was so much fun jamming to that song. How often do you get an original song and actually get to perform it?”

“The looks we had in the episode were so cool,” Zamata adds. “And the actual room too! I thought, 'I want to take this couch.' Oh, I want to take this lamp!'”