'Wicked' creator Stephen Schwartz has penned new songs with Ariana Grande and Cynthia Erivo

Schwartz told RadioTimes.com: "The creative team, led by [director] Jon Chu, has been fantastic, and I have a great music team, many of whom came from the show originally.

"And then we have this phenomenal cast - particularly our leading ladies in Cynthia Erivo and Ariana Grande are such great singers, such great musicians and wonderful human beings to work with."

Continuing to gush over the leading ladies, he added: "It's just been a privilege to be able to write with the voices of Cynthia and Ariana in mind."

Cynthia recently gushed that she is "endlessly grateful" for her role in 'Wicked'.

The 'Mr Selfridge' actress told fans she's found it hard to express how she feels about portraying "this beautifully complex being that is Elphaba", but revealed she has been reduced to tears on many occasions because she feels "proud" of what her character represents.

Sharing a photo of her hand sporting long green nails on top of a script for the second instalment of the story, she wrote on Instagram: "I realize I've said very little about my experience on Wicked and that's mainly because I've been keeping my head down and mining this beautifully complex being that is Elphaba, and it's really hard to put into words.

"It is day 111 and yesterday we finished filming 'I'm Not That Girl' when we had come to the end of that moment, my heart broke open and tears fell. (Please know this happens OFTEN).

"I thought of us, the ones who often feel like they're on the outside. The ones who don't know that their differences, oddities, quirks are what make them beautiful and special. The ones who, for some reason, believe they can't be loved and I felt proud to sing a song that might speak to those feelings.

"I am endlessly grateful to play a role that turns the notion of what beauty is on its head, I am endlessly grateful to be working with some of the most beautiful souls on the planet and I'm already grieving for the day our little bubble must come to an end (sic)"