WARNING: This article contains spoilers for the latest episode of Gotham, "That's Entertainment."
In last night's episode of Gotham, the debut of Bruce Wayne's first proto-Batmobile and the arrival of the Joker weren't the only big developments in terms of introducing more elements of the Batman mythos. There was also a much-harder-to-miss reference to the storied legacy of Batman that is almost certain to become a fan-favorite moment; the Batman '66 theme song now exists in Gotham canon.
In "That's Entertainment," Jerome escalated his war on Gotham City by crashing a rock concert that was taking place near the docks. With the help of his cronies, Jerome disposed of the band that had been playing and proceeded to terrorize the audience, threatening anyone who would leave with assured death. Then, the real show began: Jerome brought his kidnapped victims on stage, and demanded the presence of James Gordon.
A little later in the episode, at around the 12:55 mark, Gordon finally arrives on the scene. As his police cruiser approaches the gathered crowd, we can hear the familiar notes of the 1966 Batman live action series theme song. Before long, we learn that the song is being played by Jerome and his cronies on stage. No, they don't actually sing the words "Na na na na" or shout "Batman!" but there's no mistaking the music.
The song only plays for a few seconds, which makes it a little difficult to catch, especially if you're not listening for it. Still, it's a clever and fun homage to the live-action series that started it all, making one of the campy series' most iconic elements official Gotham canon. With any luck, the song will catch on, and the Gotham City residents will be humming it in the streets when they see a familiar signal in the sky.
Airing Thursdays at 8 p.m. ET/PT on Fox, Gotham stars Ben McKenzie as James Gordon, Donal Logue as Harvey Bullock, David Mazouz as Bruce Wayne, Robin Lord Taylor as Penguin, Camren Bicondova as Selina Kyle, Erin Richards as Barbara Kean and Sean Pertwee as Alfred Pennyworth.