Ethan Slater thinks Ariana Grande is an "incredible" performer

He told 'Extra': "They're amazing, they're powerhouses, they're like voices of a generation.

"Everybody knows what incredible singers they are. You think they're really different singers and then they sing together and it sounds like one voice, which is like a beautiful metaphor for them in this movie.

"They're also just really connected actors and they're really generous scene partners, and getting to work with them was just like a master class. I felt like I learned something every single take from both of them."

Ethan relished the experience of starring in the movie, after seeing the stage production for the first time back in 2004.

The actor explained: "It meant a lot to be able to become part of this family and become part of this legacy."

Meanwhile, Ariana recently revealed that her "relationship to make-up" has been transformed by her 'Wicked' role.

The 31-year-old singer plays Galinda Upland, a popular young woman who becomes Glinda the Good Witch of the North, in the new musical fantasy film, and Ariana admitted that the project has had a big impact on her own sense of style.

The award-winning star said in an Instagram video: "This make-up made me transform my entire look and my entire relationship to make-up. I just love it so much. Love, love, love."

Ariana subsequently explained how her style has evolved over recent times.

She said: "There's no thick eyeliner, there's no heavy crease, it's just really warm and open and pretty.

"The lashes are in a cat [eye] shape, which still gives you the cat eye lift that I usually love, but it's a more honest representation of what you look like."