The Vocal Coach Who Helped Timothée Chalamet and Other Stars Sing Onscreen

“Help” is a word that the vocal coach Eric Vetro uses often to describe his contributions to the careers of celebrities. This season alone, he’s helped several actors with the musical demands of roles as varied as Maria Callas (Angelina Jolie in “Maria”), Bob Dylan (Timothée Chalamet in “A Complete Unknown”) and a young Good Witch of the West (Ariana Grande in “Wicked”). He also worked with Monica Barbaro to honor Joan Baez’s vibrato in “A Complete Unknown” and Nicholas Galitzine to become a boy-band dreamboat in “The Idea of You.”

During a recent video interview, Vetro’s high-profile résumé came into sharp focus. The memorabilia behind him in his Los Angeles home, which was unaffected by the recent fires, included a guitar that Shawn Mendes had given him. He proudly pointed to platinum records from the Recording Industry Association of America certifying a million in sales for Ariana Grande’s single “The Way” and Rosalía’s album “Motomami.” Then he turned to a wall of selfies with his famous students: “There is Katy Perry. Camila Cabello and Sabrina Carpenter are right here.”

He explained that his clients’ technical and emotional needs vary, and that holding their hands through the psychological ups and downs of being a famous talent is a big part of his work. So many jobs “rest on this one person’s success,” Vetro, 68, explained. “That’s a tremendous amount of pressure.”

While growing up in upstate New York there were early signs that Vetro was more into behind-the-scenes guidance than stardom. He would correct a cousin while they sang Christmas carols and lend a hand to friends learning songs for musicals. As early as fifth grade, when a fellow student who was popular and athletic asked him for assistance with a song, Vetro remembered, “We just bonded. And that made me think, ‘I have something special here. This is my identity.’”

His parents were skeptical, especially his father. “He would say things like, ‘What makes you think that anybody of note would want to work with you?’” when as a boy he would bring up stars like Bette Midler as examples of people he wanted to work with.

Fast forward to today, and Midler is now a collaborator of more than 16 years. Other well-known clients include the Oscar winners Austin Butler for “Elvis” and Renée Zellweger for “Judy.” This awards season though, after training multiple contenders, he seems especially stirred by his work with Jolie. “She spends a great deal of her time helping other people,” he said. “She puts everybody at ease.”

At first, Jolie was blocked and fearful vocally. “She actually broke down and cried,” Vetro recalled. His priority was getting her to understand her own voice to confidently hit high notes. While it’s almost entirely Callas’s singing voice in “Maria,” Jolie sang her arias live on set, with the director Pablo Larraín using bits of Jolie’s voice in the mix.

“Eric helped me to find my voice,” Jolie, an actual soprano, wrote in an email. “I had never done the kind of work we did over seven months. He explains and is patient, but he is very serious about music. His passion is contagious.”

Vetro added, “The thing that was so hard: she had to sing exactly like Callas, holding the notes the same amount of time.” The diligent work included studying a recording of a master class Callas taught and sessions with Vetro and the opera singer Lori Stinson. Finally one day they had “that ‘aha’ moment when her voice opened up.”

Jolie recalled, “Eric pushed me and that was the kindest thing he could do. He helped me to take myself seriously as a singer.”

“A Complete Unknown” was a reunion for Vetro and Chalamet, who had worked together on “Wonka.” Vetro explained his philosophy: it’s not about impersonation but capturing the unique essence of the performer.

Even as a rising singer-songwriter, Dylan combined a youthful voice and an old soul, Vetro said, adding, “Most people don’t have that in their voice, but Timmy caught onto it quickly.” During their sessions, the two vocalized like Dylan through songs and speech, doing constant comparisons with Dylan recordings. “Each week, Timmy captured it a little more.”

With Galitzine, Vetro’s aim was to match the potential of his voice to that of a boy-band star’s. “We tried to find that heartthrob energy that girls are going to scream for,” Vetro said. “But his character is much deeper than that, so I wanted to bring that into his voice.” Working with songs by the experienced hitmaker Savan Kotecha, they considered “how a mature relationship would change his singing. I wanted it to look effortless.”

With Ariana Grande, “it was never about making her a great singer,” Vetro said, praising her talent. Instead, his goal was to teach her the delicate art of healthy singing, maintaining her voice across a long career. Wanting to protect her daughter’s voice, Grande’s mother was hesitant about singing lessons. But Vetro’s aim was to perfect the traditionally operatic sound of Glinda, with proper emphasis on high notes. Practicing the catchy, humorous “Popular” was especially fun. “Ariana would try different things every time. They were all hilarious. Laughing so hard, I could barely play the piano sometimes.”

Vetro isn’t interested in helping only established performers. He started the BBC Maestro courses online to pay his career good fortune forward with 108 vocal exercises anyone can try. He also created a scholarship program at Gloversville High School — both to provide financial support, and to raise the confidence of someone the way his own music teacher raised his. The money can go for voice lessons, schooling, even rent. “I wanted it to be for anybody who wanted to pursue a career in the arts. It might inspire them to think, ‘If this stranger believes in my talent, maybe there’s going to be other people who do, too.’”

It’s all part of his passion for music, a delight he wants his famous students to share, he said: “If you enjoy what you are doing daily, that is the biggest win, more exciting than an Oscar or Grammy.”