Quentin Tarantino, Leonardo DiCaprio on Phone-Free Sets, Scene Improvisation

As part of a nationwide 'Once Upon a Time in Hollywood' event Saturday, a Q&A was held, including Brad Pitt and Margot Robbie, in Los Angeles and live-streamed to select theaters across the country.

One of the most memorable moments in Once Upon a Time in Hollywood is Rick Dalton's (Leonardo DiCaprio) frantic meltdown in his trailer after he forgets his lines while shooting a pilot for the Western series Lancer. As it turns out, that scene was not in the original script, and was added by writer-director Quentin Tarantino at DiCaprio's behest.

The star told the filmmaker, "I need to fuck up during the Lancer sequence, and when I fuck up during the Lancer sequence, I need to have a real crisis of conscience about it and I have to come back from it in some way," Tarantino remembered at a post-screening Q&A on Saturday in Los Angeles. "My response was, 'You're going to fuck up my Lancer sequence?! That's my Western! I get two-for-one in this movie — I snuck a Western in here while no one was fucking looking!'"

To appease both parties, Tarantino shot the scene both with the forgotten lines and without, deciding that "with the fuck-up, it was just so amazing that of course we were going to use it," and then went about crafting the trailer tantrum, deciding to mostly leave it up to DiCaprio to improvise. The director wanted to do three continuous takes with DiCaprio in crisis, and planned to cut together the best bits ?— he threw out topics to his star but DiCaprio was left to do the rest. For example, Tarantino would say, "Get pissed off about Jim Stacy," and DiCaprio would respond, "Oh, that fucking Jim Stacy, just sitting up there watching me, thinking he's so fucking hot, he wouldn't be a wrangler on my show." Recalled Tarantino, "The cutest part was how nervous [DiCaprio] was to do it — I've never seen him so nervous."

The Q&A, which featured Tarantino, DiCaprio, Brad Pitt and Margot Robbie, was held at Tarantino's New Beverly Cinema theater and was part of a nationwide event where the (phone-free) moderated discussion was live-streamed into select theaters across the country. Much of the conversation revolved around Tarantino's unique filmmaking process, which included giving DiCaprio a rigorous film education and transforming current-day Los Angeles into the 1969 version of the city.

Noting how nothing in the film uses CGI or greenscreens, DiCaprio said, "It's like nostalgia within nostalgia, because we're doing a film about Hollywood in 1969, and then we're also doing a film that is done the way they do it in 1969," while Robbie added, "I don't think I've ever felt so transported as I did on Quentin's set." Part of that, the actress explained, was due to Tarantino's no-phones-on-set rule, which prompted Pitt to share an "epic" story from working with the director on 2009's Inglourious Basterds.

"You have to check your phone in — there are no phones, this is sacred ground — and one went off in between takes and you would've thought someone went into the Sistine Chapel and took a shit," the actor joked. "Not only did production come to a grinding halt — and no one would cop to it, even though we knew the general area — Quentin sent us home for the rest of the day and we had the afternoon off to think about what we had done."

"I ask you for one thing, and if you have no more respect for me than that, then go home," Tarantino said in justifying the situation, while Pitt mic-dropped in response.

Once Upon a Time in Hollywood — which follows the lives of fading Western TV star Dalton and his stuntman Cliff Booth (Pitt), all while navigating a changing Hollywood and the arrival of the Manson Family — also features many A-list actors in minor roles, including Al Pacino and the late Luke Perry. DiCaprio, who acted opposite both in the film, remembered that he was "brought back to my teenage past and felt starstruck" upon meeting Perry, whom he said "couldn't have been a gentler soul."

The star also revealed that though his and Pacino's scenes account for just a few minutes in the movie, they were shooting together for almost three weeks and DiCaprio "got to rehearse with Al at my house and his place for months beforehand because we had these long sequences together, and that was just a magical moment, one-on-one with Al Pacino."

Pitt, whose character spends some significant screen time at the notorious Spahn Ranch — where he checks in on George Spahn (Bruce Dern) — chatted about working with Burt Reynolds, who was set to play the part of Spahn before his death in September 2018. "We got to spend two glorious, fun-filled days with Burt and I'm grateful for the experience," said Pitt, remembering how Reynolds himself had a famous friendship with his own stuntman, Hal Needham, and "he told us a lot of stories about their relationship."

Robbie also spoke about getting into character as Sharon Tate, which was "beautiful in its simplicity," but challenging in achieving such a light, carefree performance.

"I find it a lot easier to go dark, a lot easier to yell and scream and cry and do all of that onscreen — I can get there a lot quicker. To be truly light all the time was actually hard, weirdly hard," said the actress, while also revealing that she worked with a movement coach and "did a lot of weird stuff, like where you run around and pretend to be a cloud." Robbie also made a list of everything that made her happy and would try to do all of those things on shooting days, as well as rules like she "couldn't look at emails within 24 hours of going to set" to cut out stressors.

Once Upon a Time in Hollywood, which premiered at Cannes and opened July 26, was recently rereleased in theaters with 10 minutes of extra footage.