The 'Once Upon a Time in Hollywood' Trailer Makes a Chilling Secret Reference to Charles Manson

In addition to darkly witty dialogue and outlandish action sequences, Quentin Tarantino‘s films are beloved for their rich soundtracks packed with deep cuts and little-known vintage gems. The inclusion of “Miserlou” in his breakout 1993 film Pulp Fiction famously gave new life to the recently departed Dick Dale‘s surf classic, “Miserlou.” But the new trailer for his latest epic, Once Upon a Time in Hollywood starring Brad Pitt, Leonardo DiCaprio and Margot Robbie, contains a haunting musical secret.

Set in — where else? — Los Angeles in the summer of 1969, the semi-fictionalized film stars DiCaprio as actor Rick Dalton, with Pitt as his longtime stunt double Cliff Booth. As the two struggle with the changing Hollywood landscape, the plot intersects with the true life story of actress Sharon Tate (played by Robbie), who was murdered by followers of Charles Manson on the night of Aug. 8, 1969 at the age of 26.

The clip, released Wednesday, kicks off with the jangling guitar and bass groove of “Straight Shooter,” a track by the group the Mamas and the Papas found on their 1966 debut.

At first listen, the song perfectly sums up the sunny L.A. scene before the specter of Manson and his followers cast a pall over the peace and love. But the soundtrack has a more sinister implication. When investigators combed through the living room where Sharon Tate lay dead at 10050 Cielo Drive on the morning after the murders, they found a grand piano mere feet from her body. Resting on the music stand was the sheet music for “Straight Shooter.”

Tate and her husband, Polish director Roman Polanski, were friends with the Mamas and the Papas, who had scored hits like “Monday, Monday” and “California Dreaming” earlier in the decade. In fact, the trailer references a party at the house of Mama Cass — the vivacious vocalist who presided over the vibrant Laurel Canyon artist scene like a hippie Gertrude Stein.

Polanski and Tate were also close to the group’s married members, John and Michelle Phillips — perhaps too close. Shortly before Tate’s death, the filmmaker had a brief affair with Michelle while in London scouting locations for a film. In the aftermath of the murder, a devastated and confused Polanski suspected John of orchestrating the crime as revenge for sleeping with his wife. John claimed Polanski threatened him with a meat cleaver, and the director himself later admitted that he would drop by the Phillips’ home, ostensibly just to visit, in order to sneak into their garage and check for blood splatter on their cars.

“I was looking for someone who knew us, who somehow was connected to us,” he said in a 1983 interview.

“It didn’t occur to me that these people would be outside our circle. During that period when I was very close to the police…I was also looking for any trace of blood in cars of people that I knew. I had chemicals that I could smear and check if there were any traces of blood on the pedals or steering wheel or seats or whatever. So I spent my nights in the garages of my friends just going through those cars. And of course I didn’t find anything. But I did think, ‘It must be someone who knew us.’ And as it happened, it wasn’t.”