Through her many roles, Idina Menzel finds herself

Idina Menzel has adopted a lot of identities during her nearly two decades on Broadway and beyond.

She originated the roles of Maureen Johnson in “Rent” and Dorothy in “Summer of ’42,” Amneris in “Aida,” Elphaba in “Wicked” and Elizabeth Vaughan in “If/Then.” She’s been Shelby Corcoran in “Glee” and the voice of Elsa in “Frozen,” singing the massive, five-times platinum hit “Let It Go.”

Along the way she’s won a Tony, Drama Desk and Grammy awards, among others.

So when Menzel steps onstage to perform as herself — as she’s doing during her current world tour — she faces the challenge of separating the performer from the characters.

“I really feel that there’s a common denominator, and that is me,” Menzel, 44, explains by phone from her home in the New York area. “Whether I’m in green makeup as a witch (in ‘Wicked’) or I’m just standing up there in my jeans and bare feet, singing my songs, as an artist I still have to take a risk and make myself really vulnerable in front of a live audience and allow myself to be seen, if you will.

“And I feel that way whether I have the green makeup on or I don’t, or I’m hiding behind a character or singing the character’s words. It’s still the soul of who I am that connects it all.”

Menzel — whose name was famously mispronounced by John Travolta during the 2014 Academy Awards — began that journey of finding her voice as a teenager growing up in Syosset, N.Y., where she was born Idina Mentzel and sang at weddings and other social affairs. She attended New York University’s Tisch School of the Arts and successfully auditioned for “Rent” in 1995, an auspicious career start for which she won her Tony Award for Best Actress in a Musical.

Since then, Menzel explains, she’s learned how to sing and perform spontaneously, even in scripted roles.

“Every song, every show, every character, project whatever it is, it’s a different part of the chronology and time in your life, and so it changes,” she says. “A certain song can hit me in a different way on a different night or a different time in my life, so I leave myself open in that way and a lot of times I discover things in front of thousands of people.

“In the beginning, when I was younger that was frightening to do that. But I learned that’s the only way you can be, that you really can connect with people if you allow yourself to be vulnerable in that way. I think that’s what’s so beautiful about what I do.”

Performing the moment can have its own, well, moments too, however.

“Oh, things go wrong all the time,” Menzel acknowledges, “everything from my boobs coming out of my bra in front of people at Radio City Music Hall to forgetting the words, or somebody yelling something from the audience that strikes me in a funny way and we have a conversation.

“I think being a creature of the theater and doing eight shows a week, you embrace those things that make you fresh, that keep you on your toes. I enjoy that.”

Not surprisingly, Menzel keeps her concerts a bit loose. “I don’t want to do the same exact thing every night,” she notes. That said, however, there are things that do have to happen at each show — especially “Let It Go,” which elevated Menzel’s stature well beyond the theater realm.

“I knew it was a beautiful song when they sent it to me to learn, but I had no idea it would have this effect and become the kind of phenomenon that it’s become,” Menzel says. “It’s wonderful to have a song that’s obviously heightened my profile and helps people get to know me better and on a deeper level and give some more opportunities and all of that.

“But the beautiful thing about it is that as much as it speaks to young people it also speaks to me as a woman and as a reminder for myself of the things that I think are important and the things I need to learn — for instance, the idea of really not hiding those things that make us really wonderful and extraordinary and that set us apart in the world just because we’re afraid of seeming threatening or being disliked.”

Of course, “Let It Go” is bringing an even younger crowd to Menzel’s shows, which can create some delicate situations.

“Between ‘Rent’ and ‘Wicked’ and even ‘Glee’ and now ‘Frozen,’ I’ve always had to figure out how to negotiate, navigate around a wide demographic — which is obviously a very lucky thing, a gift, but also can be tricky,” says Menzel, who has a 5-year old son, Walker, from her 11-year marriage to “Rent” co-star Taye Diggs. “I’m a 44-year-old woman up there on stage and I curse, I swear about something and then I realize that’s a mom in the front row with her little 8-year-old daughter in an Elsa costume.

“But I have to be myself, too. That’s a challenging thing is how I reconcile all of that.”