WHEN ASKED WHERE she’d like to meet for lunch, Idina Menzel selects Union Square Cafe in Manhattan, where the multi-hyphenate performer worked as a reservationist before becoming a Broadway star “I was really bad at the job,” she recalls, “but I loved the people and the tuna burger. Still, you can’t believe the vitriol thrown in your direction when you said, ‘I’m sorry, I don’t have a reservation at 8:30 on a Saturday night for another six weeks.’”

This was, Menzel recounts, just one of many unglamorous pre-Broadway jobs. “I was a wedding singer and also worked on the Spirit of New York, a cruise ship. At any given moment, you might be ‘on,’ which meant turning your vest inside-out — it was red satin on the inside — so it became a showtime vest. You’d drop your tray and sing a song with the house band, like ‘Saving All My Love for You’ by Whitney Houston. I was a terrible waitress, but hopefully, I sang well enough to win them over.”

These days, of course, Menzel is living a different kind of life. Her star-making turns in “Rent” and “Wicked” (where she originated the role of Elphaba, garnering a Tony) have made her a Great White Way fixture, which, in turn, has provided her with sanity in a notoriously fickle industry. “The theater gives me consistency. I arrive at the same time every day. I warm up for 35 minutes, and do the same vocal exercises. I put on my makeup. I go over my notes, my lines, then do the show. It can be a very hard job, but it can also be your sanctuary. Sometimes it’s a relief to be on stage, listen to somebody else sing, and just react, especially if you’re someone (like me) who exhausts herself by listening to her inner saboteur.”

Menzel is also a recording artist and a movie star, recently popping up opposite Adam Sandler (in “Uncut Gems” and “You Are So Not Invited to My Bat Mitzvah”). But it is her turn as the voice of Elsa in Disney’s “Frozen” — and the ubiquity of “Let It Go” — that has made her a true cultural phenomenon. When I posit that there will now be a generation growing up with her voice as their first remembered example of a singer, she simultaneously beams and shrugs. “I don’t take that lightly. Even though I like to tackle different styles, I still think I sound like myself whatever I’m doing. The most important thing is that when you hear my voice you know, ‘Oh, that’s Idina.’ All I ever wanted was to have a voice that had its own unique sound.”