"Part of Your World" is a song of questions.

How many wonders one cavern can hold. What it costs to spend a day on the sand. What the word is for that thing fire does. All of them building to the ultimate ask: "When's it my turn?"

In the 1989 animated classic "The Little Mermaid," Ariel as voiced by Jodi Benson delivers the lyrics with a wistful, resigned sigh. In Disney's live-action remake, Halle Bailey attacks the song's climax with a powerful ascending vibrato, and holds on long after the orchestra drops out.

By the time she finished, director Rob Marshall was in tears. "When she sang, you got a deep understanding of what it is that Ariel wants, you believe that the stakes are high, and you just root for her to succeed," he said.

"I think we all go through the things Ariel goes through: feeling uncertain but passionate about our future, knowing when we want something great for ourselves and what lengths we'll go to get it," Bailey said.

Bailey, just 18 at the time of her audition, was "shocked" by the production's interest in her. "If I would have seen a Black mermaid when I was younger, it would have changed my whole life," she said, calling the animated movie a childhood favorite. My whole perspective on how I feel about myself, my self-worth, my confidence, everything."

There were some reasonable doubts along the way, given that each section of the film presented Bailey with a distinct set of obstacles. To film Ariel's underwater sequences, she repeatedly simulated swimming motions while suspended in harnesses and tuning fork rigs. For scenes at the surface, Bailey spent a month diving into water tanks over and over again.

Bailey also had the unique task of re-creating the original movie's iconic shots. To capture the visual for the "Part of Your World" reprise's final crescendo, the production design team created a fake rock tailored to her body's measurements and outfitted with a softer texture so that she could hold herself up in a plank position while filming the moment off the coast of Sardinia, Italy.

And there was the COVID-19 pandemic. "Everything was closed down, so I would just go to work and then go home on the weekends, and then do it all again for weeks and weeks and weeks," said Bailey. "I would literally sleep the whole weekend because of how tired I was, but I also ended up feeling very isolated.

"I was really thankful to God because it really aligned with the way Ariel would feel when she was alone in her grotto, but still wanted to reach for the stars," she continued. "I appreciate that, in the end, it helped me feel more connected to her."

Now 23, Bailey is still processing the intense, introspective adventure she's had in the years since that auspicious audition.

"Going into the film, I was more timid and shy, but like Ariel, I ended up having to come out of my shell. I gained so much confidence and courage to speak up for what I need; I came out a different, more mature human being. I really feel like Ariel taught me how to find my voice."