This winter, Disney fans are in for a real treat with Frozen. It’s a fairytale feature where we get not one, but two heroines! Idina Menzel (Wicked) and Kristen Bell (Veronica Mars) voice sisters Queen Elsa and Princess Anna. They’re torn apart when Elsa (Menzel) loses control of her ice powers and is exposed to her kingdom, when she accidentally encapsulates it into an eternal winter. While she’s seen as a monster, her sister Anna (Bell) is determined to get through to her and repair the damage.

The amazing people behind Frozen promise to bring a tale of two sisters who’d do anything for each other. ScreenCrave went behind the scenes at Walt Disney Animation Studios and spoke with the film’s creative team.

Head of Animation Lino DiSalvo on bringing in Idina Menzel to meet the animators in order to give her character her real-life traits:

Lino DiSalvo: I’d moderate like an Inside the Actors Studio. We’d talk about technique, singing and breath. It was a huge thing for us [animators] on this film. It’s something that we very, very much wanted to get right. So, having Idina come in, talk about her singing technique — which is something that was very important to us — because obviously the Elsa character sings an amazing song.

Elsa animator Wayne Unten describes detailing the performance of the song “Let it Go” with Menzel’s physical technique:

Wayne Unten: So, like if you notice like when she’s singing, she takes a breath. And then when she says ‘Past is in the past,’ there’s this thing she does I’m taking from her performance that’s really cool. You notice she takes a big breath. See it in the diaphragm. You can see like all the neck tension. If it makes it more believable, I’ll put it in there.

How Kristen Bell’s personality aided Anna animator Becky Bresee:

Becky Breese: I think the voice lends itself well, so you are taking bits and pieces. And, you know, she’d do things like she’d bite her lip a lot, and so we put that into the character. She is very… perky, yes. Yeah, it worked well for her.

Art Director Brittney Lee on creating the look of Anna:

Brittney Lee: So, I grew up on Disney fairy tales, and it’s absolutely been a dream to be able to work on this film. All of the female characters are wearing petticoats and undergarments. And a lot of that was informed by the research (of Norwegian garments). We were able to look at these and sort of realize what materials we needed them to be. It couldn’t be the same types of dresses that you would see Rapunzel in because her climate was very different, and Anna would freeze if she was wearing those satins. So a lot of our fabrics are much heavier. They’re wools and velvets, and they have more structure so they don’t necessarily twirl the same way that Rapunzel’s dress would twirl, so we add fun by adding structure in a way that allows movement. So one of Anna’s dresses is pleated and she can twirl all she wants, and  it’s breathtaking when she does. But another way that we add fun to the costumes is by giving every character Rosemaling to make them feel like they both fit in this world, but they can also be specific to each character. So Anna is a playful, happy-go-lucky character, and so she has very playful, happy-go-lucky Rosemaling. It’s mostly floral based, and it’s consistent for her in almost every costume she wears throughout the film.

Lee on the challenges of creating a unique look for Elsa:

Brittany Lee: Our last challenge with costuming was Elsa, because once she goes to her ice palace, there are no rules anymore. She is essentially breaking from everything she knows, so what she ends up wearing has to be very different than what she wears before, but still speak to her language and where she’s come from. So the way we decided to tackle that with Elsa was to use the snowflake and use the graphic symbol of the snowflake to replace her Rosemaling. So she has details of snowflakes, but then she also has the shape of her cape is actually. If you were to lay it flat on the ground, it is an entire snowflake. She is completely enveloped in this new world of hers.

Director Chris Buck on what made Menzel the right fit for Elsa:

Chris Buck: We always thought, ‘Who could do this?’ you know? Because we knew that the songs were gonna be outrageous. And just that character, the strength of her. Of course had seen her in Wicked and knew what an amazing talent she was. The character of Elsa is so powerful and yet there’s a really vulnerable side to and Idina’s the same way. Her persona is very powerful and it comes out in Elsa as well as you know, this vulnerable side. She nailed it. It was beautiful. We did a table read where we had Kristen Bell and then Idina Menzel. They read through the script, of course it was wonderful but we had no songs yet. We had to show the power of the music in this, for this film. And they sang this beautiful song. They sang it to each other, Kristen and Idina, and there wasn’t a dry eye in the house. It was just—it was magical.

Producer Peter Del Vecho and Directors Buck and Jennifer Lee talk about the importance of having the actresses record together:

Jennifer Lee: I mean it was really a two-year process with them. What we do is every 10 to 12 weeks we put the movie up in storyboards or whatever form it’s in and we re-record the dialogue as much as we can with the actors. So we were re-recording with them a lot. On the key emotional scenes, particularly for Kristen and Idina, we wanted them together.

Peter Del Vecho: We even got Kristen and Idina together for a song. That really helped elevate the song because they have a duet in the movie and it definitely helped drive that.

Chris Buck: So as much as we could, we got them in together. It just adds this real, amazing chemistry between the actors and things that they wouldn’t do on their own and they really interact. I loved it.

Frozen opens in theaters November 27.