"It sounded like such fun! What they have in mind for the opening number is absolutely spectacular," Moreno said with a laugh. "And I have the perfect song to go with the idea that they have. So everybody was delighted on their side and I'm thrilled on mine."
She wants it to be a surprise for theatergoers. "Obviously, I'm not going to give any of this away," Moreno said.
Other scheduled performers include Tony winner Brian Stokes Mitchell, Tony-nominated Megan Hilty (of TV's "Smash") and performers from Ballet West, Repertory Dance Theatre, Ririe-Woodbury Dance Company, Utah Opera Chorus and the University of Utah theater department.
Moreno is busier than people half a century younger than she is. She recently finished starring in a reboot of the 1975-84 sitcom "One Day at a Time" (slated to debut in January on Netflix) and then "decided that I was going to accept a whole bunch of offers to do either my cabaret show or talks" across the country.
"I really never dreamed that at this age I would be as busy as I am," she said. "I have an album out, which was produced by Emilio Estefan in Spanish. I have a book out on my life. I am the busiest 84-year-old woman I know."
The thought of retirement holds no appeal for Moreno, who has no interest staying home and putting her feet up.
"I am doing what I want. It's what I love. I'm performing," she said. "Why the hell would I stay home, for Pete's sake. I mean, I love my home. I have a beautiful home. I have an adorable little puppy dog, and I have a pretty damn good life. But I'm doing what I love."
Moreno's career spans more than seven decades and includes films like "The King and I" and "West Side Story," Broadway shows like "Last of the Red Hot Lovers" and "The Ritz," and TV shows like "Oz" and "The Electric Company."
By the way, EGOT-winning Moreno also has a second Emmy, a Golden Globe, a Latin Grammy, multiple lifetime-achievement awards, the Library of Congress Living Legends Award, the Presidential Medal of Freedom, the National Medal of Arts and the Kennedy Center Honors Lifetime Artistic Achievement Award — among others.
They're not displayed on the mantel of her Northern California home, however.
"The mantel isn't big enough," Moreno said. "I call it the hardware section of the living room, and it's three shelves. There's a lot of stuff there.
"Every once in a while I'll pass those shelves and I'll say, 'Wow — not too shabby.' "