For Mary Poppins Returns, one of the biggest challenges was making the spoken word smoothly transition into the musical sequences. Once the sound and music editing teams prepared all the dialogue and production tracks, singing pre-records, ADR, hard effects, ambiances, foley and music tracks, the various audio elements had to be combined in a process that makes a grounded, believable soundtrack. That was where re-recording mixers Mike Prestwood Smith and Michael Keller came in.
“We mix it all together and make it seem realistic. It starts with Mike dealing with dialog and lyrics to match them as closely as you can with reverbs and eq and all this other technical voodoo. Then we create some fill around it to make it sound like they’re in the same space,” explained Keller. “It all comes together. It’s a big team effort to make it seamless.”
It all starts with the performance and how it is recorded, but there are layers of technical tweaks that go into making it sound right. Because the film is not a “bombastic” movie, there is nothing to hide under. Scenes go from subtle production takes into prerecords, without any busy backgrounds or effects to hide the transition.
The film was first mixed in 7:1 stereo, the most common release format for the most screens, but to best bring the audience into the middle of the high-production value musical sequences, the mixers also spent a week recording a Dolby Atmos up-mix.
“As we mixed the movie the first time through, we always thought of Atmos elements we could later either put in the ceiling or put as an object somewhere else,” shared Keller. “The music benefited the most from the Atmos. Full range surrounds gave it another level. It becomes fuller, rounder. It opened it up. You can go more pin-pointy in a Atmos.”
“Trip the Light” was Keller’s favorite scene to mix. Normally two foley walkers will foley the whole movie. For this film, the choreographers trained eight dancers to re-dance all the numbers with proper shoes on floors of varying materials – slate, gravel, iron – to match the visuals on the screen. Because the choreographers who knew the dances came in, sounds, such as the canes, hand pats and snaps, were recorded in the foley session. These elements otherwise might have been missed with everything else happening onscreen.
“It was the best foley I’ve heard,” commented Keller. “It’s a percussion element in the music more than anything because some slide, others have a steppy sound which is more percussive. They jump on the lamps and then you’ve got metallic footsteps and hands and clothes that are in rhythm.”
Because of all the competing elements, the chase on the bowl was the most challenging sequence for the mixers. Music is playing loud. The kids are talking and screaming. There is the steady chuffing of the Stanley Steamer that gets boring in a scene that needs to escalate, so it turns into a steam engine, and then into an angry wolf. “And you have to create the terror that they are going through a crack, not spinning out of control. All in a ceramic bowl,” said Keller. “It’s a long scene. That was quite complicated to do.”
The closing musical sequence with everyone singing as the balloons take them into the sky was a big mix moment for Prestwood Smith and the music department. Each character was on a separate track. As a character floats by their voice is raised and equalized. Then they fade out and the next character’s voice takes precedence. “It’s such a big ensemble. If you play them all, it’s just a wall of noise,” stated Keller. “You just feature the person that matters or the person that’s the closest.”
Mary Poppins Returns is not just a film to be seen. It is an experience to be heard.