Three Is a Magic Number is the pilot episode of the Schoolhouse Rock! series and the first episode of the program's first season, "Multiplication Rock." The title song, written by Bob Dorough, and accompanying animated video were created after ad agency co-chairman David McCall observed that his son had learned every Beatles lyric but could not remember multiplication tables.
Ready Player One History
The lyrics, coupled with the hidden message found on Syrinx from obtaining the Crystal Key, indicate that three unique copies of the Crystal Key are necessary to unlock the Third Gate. Additionally, when three avatars are in front of the Third Gate, one of them must recite "Three is a magic number" in order to unlock the gate for the present avatars to enter through.