It was today announced that the US singer will be coming with the musical in its February transfer from New York to London to make her West End debut.
She revealed she has been longing to tread the boards here since seeing Cats on a trip to the capital when she was 12.
The 34-year-old had her big break when she was the runner-up on American Idol in 2006. As well as releasing several albums, she has acted in TV shows including Stephen Spielberg’s Smash and action drama Scorpion.
She made her stage debut in the Broadway production of Waitress, playing the main character Jenna, a pie-maker who dreams of a way out of her loveless marriage. It is based on the 2007 film of the same name.
McPhee said she was a “mixed bag of emotion” about bringing the show to the Adelphi Theatre.
She added: “I don’t even know where to begin. When I was first asked I just couldn’t believe it ... I still remember sitting in the audience as a little 12 year old on my first trip to London watching Cats the musical.
“I’m anxious to get there and get started. It’s a big responsibility to carry a show like that. The story is such an amazing story to tell and I take it very seriously.”
Waitress plays at the Adelphi Theatre from 8 February. Tickets from waitressthemusical.co.uk