Three years ago, I packed up my things at my desk in a Sacramento television news station and walked out of the building jobless.

I’d spent the first nine years of my career in journalism, but left emboldened by an idea for a documentary I hoped to see through—the secret lives of the world’s most famous musicians.

“Musicians” is a severe understatement. The idea was to capture a part of how composers of the world’s most iconic films and television programs craft music that makes us cry and gives us goosebumps. Or perhaps music that lifts the spirits of millions of people every day in movie theaters, theme parks and even sports arenas. We live in a world that is scored, and I intended for Score: A Film Music Documentary to unravel some of the creative secrecy behind these maestros of the modern age.

What followed was two years of interviews with composers like Hans Zimmer, Randy Newman, Trent Reznor and Quincy Jones. In all, more than 60 interview subjects—many eager to share what’s been bottling up for decades in their soundproofed music studios. Though most will never be recognized on the street, the superstar talent is undeniable to anyone seeing these maestros at work.

A collaborative art form, film has traditionally praised its onscreen talent and auteur directors for popular success, but composers play a far more crucial role in allowing a film to connect with the public. These are five milestone lessons learned through Score’s dozens of interviews, spotting sessions and behind the scenes access to the world’s most beloved film composers.

Matt Schrader, director of Score: A Film Music Documentary

1. Time = Success

For decades, film music has largely been relegated to post-production. It makes sense historically, as you can’t put music to picture if there isn’t a picture yet. But early communication with a composer can yield wildly inventive results that enhance the film beyond even the director’s ideal vision. Composer Hans Zimmer worked with Christopher Nolan on the score for The Dark Knight before the characters had even been established yet. Composer James Horner began work on James Cameron’s Avatar years before any of the final edits were complete. Conversely, while there have been landmark scores written and recorded in just several days, these scores are not able to build in the kind of musical ideas possible with pre-planning. Composer Tyler Bates composed music that was played on the set of Guardians of the Galaxy, allowing actors to sync to the mood and pace of the music. These kinds of early collaborations help to enhance the scope of what the score can accomplish, and avoid the pitfalls and time-crunched roadblocks often faced by filmmakers when the score is treated as a spice or seasoning rather than as its own gourmet dish.

2. Find Your Shorthand With Your Composer

In speaking with the late Garry Marshall in one of his final interviews, the topic of composer chemistry came up. Equally important to a composer’s abilities is his chemistry with the director. “You’ve got to be able to eat together,” he said with a laugh—an oversimplification of the kind of friendship and emotional support that must exist between a director and composer. In Marshall’s mind, and in the mind of many composers we interviewed in Score, it’s crucial to get on the same wavelength as early as possible. Almost as in a professional courtship, the goal is to understand each other’s emotional visions and meet somewhere in the middle to bring out the best possible result. “A composer has to be almost like a therapist,” director James Cameron told our team. Only when there is a comfort and understanding between collaborators can the good ideas start to flow freely, but it’s important to develop that connection or “shorthand” language. Marshall found this is John Debney, who learned to adapt his own skills to enhance Marshall’s creative priorities and strengthen his insecurities. Debney notes that once he developed this rapport with Marshall, a single glance could say more than 10 minutes of conversation.

Composer John Debney, director Garry Marshall and other crew in Score: A Film Music Documentary

3. Make Sure All Ideas Are Welcome

It can be difficult for a director to have an open mind once he’s shot and edited a scene. Making matters worse is the modern trend of using temp music when first showing the film to a composer—something composers almost universally detest. Remember that scores shouldn’t sound like any other story from the past; they should sound like the story you’re telling. Giving your composer a music-free cut of the film allows them to use their expertise as intended. Additionally, refrain from giving too many constraints before the composer has written any music. Trust them to do what they do, and remember they’re there because they can do things most director’s can’t. Zany musical ideas can always be reined in, but it’s hard to make a boring musical idea interesting again. Films like E.T. and Gladiator have succeeded with bold, unorthodox musical choices, but only because their directors gave their composers freedom to experiment with something truly new.

4. Composers Are Filmmakers Too

Any screenwriter will tell you the importance of a well-crafted script. You need story arcs, intensity and the structure to hold all of the many themes that recur throughout the story. The same is true with music. Composer Howard Shore discussed the importance of this with the Score team in discussing the many themes he developed for the Lord of the Rings series. When Frodo is in a distant land and sees another character from his home in the Shire, we hear the Shire theme, even though it might otherwise seem out of place in this distant land.

Composer Christophe Beck illustrated this to the Score team in his mockups for Disney’s Frozen. By establishing a mysterious magic theme early in the story, he could later work in the same theme to help the audience make a connection they might not otherwise get.

Composer Hans Zimmer at work in Score

“You should try to elevate everything that is there,” Hans Zimmer told our crew in his studio. “The story, the acting, the camerawork, and the director’s vision. And I think part of what we do is we get to tell that part of the story you can’t elegantly tell in pictures or words.”

5. Variety is King

While we put together the sequences in Score that explore different styles of film composing, it became clear how important fresh musical ideas are to film. Reused music—or music made to sound like existing music—will never be great. Each score is its own statement. While it’s evident many composers have unique traits that make their scores sound similar in one way or another, it’s the exploration and pushing of boundaries where genius happens.

As they discussed in Score, Trent Reznor and Atticus Ross won an Oscar for their music to The Social Network, which had a startlingly mismatched track in the middle of the film: an electronic rendition of “In The Hall of The Mountain King.” John Williams’ Star Wars original score is powerful and moving as a soundtrack as well—until you get to the Cantina Band track. Remember that what makes film scores unique is not only their ability to explore all the emotive corners pop music cannot, but their ability to be exactly what the story needs—whether orchestral, jazz band, the choir of “Duel of the Fates” or Antonio Sanchez’s drums-only score to Birdman.

Composer Rachel Portman in Score

And while some advances have been made, we’re entering an era in which technology allows musical experimentation to take place on a smartphone, laptop or tablet. In the future, scores won’t just be what an orchestra plays—as they largely were until the 1950s—or just what can be played with physical instruments, as they largely were until the 1980s. Evolving at the speed of the talented composers pushing the limits, scores are unrestricted by the rules of 20th-century film or today’s popular record albums—so a great film score can transcend what is necessary and reach for what truly moves our hearts. MM

Score: A Film Music Documentary opens in theaters in select cities June 16, 2017, and is now available for pre-order through iTunes or the film’s website, courtesy of Gravitas Ventures.