Once Upon A Time In Hollywood features various pop culture references ranging from films, TV shows, and songs, one of which is “The Green Door,” a 1950s song with a lot of mystery surrounding what actually lies behind the titular door. Quentin Tarantino is known for his peculiar narrative and visual style but also for adding countless references to his movies and Once Upon a Time In Hollywood is no exception.

The film follows actor Rick Dalton (Leonardo DiCaprio) and his friend/stunt-double Cliff Booth (Brad Pitt) as they struggle to stay relevant during the final years of Hollywood’s Golden Age. Throughout the story, Rick is shown taking part in different projects – from western TV shows to commercials – and one of those had him awkwardly singing and dancing to Jim Lowe’s 1956 hit “The Green Door.” The meaning behind the song has been a mystery for years and Once Upon A Time In Hollywood managed to revive it.

There have been many interpretations about the meaning of “The Green Door” since its release. The song tells of a man who spends every night awake due to the sound coming from a club with a green door. He tries to get in by knocking and telling them he’s been there before, but he’s refused entry. He sees an eyeball “peeping through a smoky cloud” and says the code “Joe sent me,” but he’s rejected again. Many people have wondered what exactly was behind the green door, and there are various theories, ranging from underground taverns to gay clubs.

In 1921, a tavern opened in Chicago called “Green Door Tavern.” It was a popular place during prohibition, and the green door became a speakeasy symbol. Another story says the song is about an after-hours club in Texas, where songwriter Marvin Moore was denied entry because he didn’t know the password. The most popular theory says it refers to Gateways, London’s first lesbian club, which had a green door and was featured in the film The Killing of Sister George starring Susannah York (Superman). Other theories say it was inspired by the short stories “The Green Door” by O. Henry from his book The Four Million, H.G Wells’ “The Door in the Wall” or Mildred Wirt Benson’s mystery novel Behind the Green Door, this last one about illegal activity happening behind a secret door at a ski-resort hotel.

However, the most logical explanation goes back to the Prohibition Era, in which many restaurants painted their doors green to signal the presence of a speakeasy – history supports this, and the lyrics make sense with this in mind. Maybe Tarantino had a different idea when he chose this song for Once Upon A Time In Hollywood, and while the world will never truly know what lay behind “The Green Door,” it most likely has to do with the Prohibition Era.

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