Coco’s sound story — music, guitars and bones

By Jennifer Walden

Pixar’s animated Coco is a celebration of music, family and death. In the film, a young Mexican boy named Miguel (Anthony Gonzalez) dreams of being a musician just like his great-grandfather, even though his family is dead-set against it. On the evening of Día de los Muertos (the Mexican holiday called Day of the Dead), Miguel breaks into the tomb of legendary musician Ernesto de la Cruz (Benjamin Bratt) and tries to steal his guitar. The attempted theft transforms Miguel into a spirit, and as he flees the tomb he meets his deceased ancestors in the cemetery.

Together they travel to the Land of the Dead where Miguel discovers that in order to return to life he must have the blessing of his family. The matriarch, great-grandmother Mamá Imelda (Alanna Ubach) gives her blessing with one stipulation, that Miguel can never be a musician. Feeling as though he cannot live without music, Miguel decides to seek out the blessing of his musician great-grandfather.

Music is intrinsically tied to the film’s story, and therefore to the film’s soundtrack. Ernesto de la Cruz’s guitar is like another character in the film. The Skywalker Sound team handled all the physical guitar effects, from subtle to destructive. Although they didn’t handle any of the music, they covered everything from fret handling and body thumps to string breaks and smashing sounds. “There was a lot of interaction between music and effects, and a fine balance between them, given that the guitar played two roles,” says supervising sound editor/sound designer/re-recording mixer Christopher Boyes, who was just nominated for a CAS award for his mixing work on Coco. His Skywalker team on the film included co-supervising sound editor J.R. Grubbs, sound effects editors Justin Doyle and Jack Whittaker, and sound design assistant Lucas Miller.

Boyes bought a beautiful guitar from a pawn shop in Petaluma near their Northern California location, and he and his assistant Miller spent a day recording string sounds and handling sounds. “Lucas said that one of the editors wanted us to cut the guitar strings,” says Boyes. “I was reluctant to cut the strings on this beautiful guitar, but we finally decided to do it to get the twang sound effects. Then Lucas said that we needed to go outside and smash the guitar. This was not an inexpensive guitar. I told him there was no way we were going to smash this guitar, and we didn’t! That was not a sound we were going to create by smashing the actual guitar! But we did give it a couple of solid hits just to get a nice rhythmic sound.”

To capture the true essence of Día de los Muertos in Mexico, Boyes and Grubbs sent effects recordists Daniel Boyes, Scott Guitteau, and John Fasal to Oaxaca to get field recordings of the real 2016 Día de los Muertos celebrations. “These recordings were essential to us and director Lee Unkrich, as well as to Pixar, for documenting and honoring the holiday. As such, the recordings formed the backbone of the ambience depicted in the track. I think this was a crucial element of our journey,” says Boyes.

Just as the celebration sound of Día de los Muertos was important, so too was the sound of Miguel’s town. The team needed to provide a realistic sense of a small Mexican town to contrast with the phantasmagorical Land of the Dead, and the recordings that were captured in Mexico were a key building block for that environment. Co-supervising sound editor Grubbs says, “Those recordings were invaluable when we began to lay the background tracks for locations like the plaza, the family compound, the workshop, and the cemetery. They allowed us to create a truly rich and authentic ambiance for Miguel’s home town.”

Bone Collecting
Another prominent set of sounds in Coco are the bones. Boyes notes that director Unkrich had specific guidelines for how the bones should sound. Characters like Héctor (Gael García Bernal), who are stuck in the Land of the Dead and are being forgotten by those still alive, needed to have more rattle-y sounding bones, as if the skeleton could come apart easily. “Héctor’s life is about to dissipate away, just as we saw with his friend Chicharrón [Edward James Olmos] on the docks, so their skeletal structure is looser. Héctor’s bones demonstrated that right from the get-go,” he explains.

In contrast, if someone is well remembered, such as de la Cruz, then the skeletal structure should sound tight. “In Miguel’s family, Papá Julio [Alfonso Arau] comically bursts apart many times, but he goes back together as a pretty solid structure,” explains Boyes. “Lee [Unkrich] wanted to dig into that dynamic first of all, to have that be part of the fabric that tells the story. Certain characters are going to be loose because nobody remembers them and they’re being forgotten.”

Creating the bone sounds was the biggest challenge for Boyes as a sound designer. Unkrich wanted to hear the complexity of the bones, from the clatter and movement down to the detail of cartilage. “I was really nervous about the bones challenge because it’s a sound that’s not easily embedded into a track without calling attention to itself, especially if it’s not done well,” admits Boyes.

Boyes started his bone sound collection by recording a mobile he built using different elements, like real bones, wooden dowels, little stone chips and other things that would clatter and rattle. Then one day Boyes stumbled onto an interesting bone sound while making a coconut smoothie. “I cracked an egg into the smoothie and threw the eggshell into the empty coconut hull and it made a cool sound. So I played with that. Then I was hitting the coconut on concrete, and from all of those sources I created a library of bone sounds.” Foley also contributed to the bone sounds, particularly for the literal, physical movements, like walking.

According to Grubbs, the bone sounds were designed and edited by the Skywalker team and then presented to the directors over several playbacks. The final sound of the skeletons is a product of many design passes, which were carefully edited in conjunction with the Foley bone recordings and sometimes used in combination with the Foley.

L-R: J.R. Grubbs and Chris Boyes

Because the film is so musical, the bone tracks needed to have a sense of rhythm and timing. To hit moments in a musical way, Boyes loaded bone sounds and other elements into Native Instruments’ Kontakt and played them via a MIDI keyboard. “One place for the bones that was really fun was when Héctor went into the security office at the train station,” says Boyes.

Héctor comes apart and his fingers do a little tap dance. That kind of stuff really lent to the playfulness of his character and it demonstrated the looseness of his skeletal structure.”

From a sound perspective, Boyes feels that Coco is a great example of how movies should be made. During editorial, he and Grubbs took numerous trips to Pixar to sit down with the directors and the picture department. For several months before the final mix, they played sequences for Unkrich that they wanted to get direction on. “We would play long sections of just sound effects, and Lee — being such a student of filmmaking and being an animator — is quite comfortable with diving down into the nitty-gritty of just simple elements. It was really a collaborative and healthy experience. We wanted to create the track that Lee wanted and wanted to make sure that he knew what we were up to. He was giving us direction the whole way.”

The Mix
Boyes mixed alongside re-recording mixer Michael Semanick (music/dialogue) on Skywalker’s Kurosawa Stage. They mixed in native Dolby Atmos on a DFC console. While Boyes mixed, effects editor Doyle handled last-minute sound effects needs on the stage, and Grubbs ran the logistics of the show. Grubbs notes that although he and Boyes have worked together for a long time this was the first time they’ve shared a supervising credit.

“J.R. [Grubbs] and I have been working together for probably 30 years now.” Says Boyes. “He always helped to run the show in a very supervisory way, so I just felt it was time he started getting credit for that. He’s really kept us on track, and I’m super grateful to him.”

One helpful audio tool for Boyes during the mix was the Valhalla Room reverb, which he used on Miguel’s footsteps inside de la Cruz’s tomb. “Normally, I don’t use plug-ins at all when I’m mixing. I’m a traditional mixer who likes to use a console and TC Electronic’s TC 6000 and the Leixcon 480 reverb as outboard gear. But in this one case, the Valhalla Room plug-in had a preset that really gave me a feeling of the stone tomb.”

Unkrich allowed Semanick and Boyes to have a first pass at the soundtrack to get it to a place they felt was playable, and then he took part in the final mix process with them. “I just love Lee’s respect for us; he gives us time to get the soundtrack into shape. Then, he sat there with us for 9 to 10 hours a day, going back and forth, frame by frame at times and section by section. Lee could hear everything, and he was able to give us definitive direction throughout. The mix was achieved by and directed by Lee, every frame. I love that collaboration because we’re here to bring his vision and Pixar’s vision to the screen. And the best way to do that is to do it in the collaborative way that we did,” concludes Boyes.


Jennifer Walden is a New Jersey-based audio engineer and writer.


3 thoughts on “Coco’s sound story — music, guitars and bones

  1. Marlis and Bob Kiser

    Very Happy to see J R Grubbs getting some nice press. What a nice boy he was growing up, and what a great talent he became. Good for him
    to be recognized like this.
    Marlis and Bob Kiser

    Reply
  2. Marlis and Bob Kiser

    Very happy to see J R Grubbs getting some nice press. What a nice boy he was growing up, and what a great talent he has become.
    Good for him to be recognized like this.
    Marlis and Bob Kiser

    Reply
  3. Pedro Lima

    Very Nice story. Is good to read about the real life and work of top artist. Their challenges and development process. Turns all of us into humans – not super humans like sometimes we see those artist.
    And all of them, including you, Jennifer Walden, do a nice work.

    Reply

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