Songbird Idina Menzel has it all – fame, fans, a tour bus and hot showers.

Broadway veteran Idina Menzel has a gorgeous, soaring voice, starring roles in two wildly successful shows – as Elphaba in “Wicked” and as Maureen in “Rent” – under her belt, a budding film career and a celebrity hubby (actor Taye Diggs). The Tony award-winning performer also possesses one quality so many other stars seem to lack: humility. Though she’s had more successes in the past decade than most people have in a lifetime, the down-to-earth diva still knows how to get excited about the little things, like getting her own tour bus. (O.K., maybe “little” is a relative term.) Menzel, 37, who began the second part of her U.S. tour July 17, talks to Style about stage fright, the married life of celebrities and taking a role from Broadway to the screen.

Style: Can you tell me a little bit about your background in singing and any of the training and experience you’ve had?

Menzel: Yeah, I started singing when I was a little kid– I don’t remember exactly when, like around 5 or 6 years old. I was just singing all the time, and I started to take voice lessons when I was a little older and studied classically. And then I studied through school. I switched teachers later on, when I was in college, [to one] who was a more pop/rock-focused teacher, as opposed to classical, and I’ve been with her for about 15 years.

You’ve written or co-written most of the songs on your latest album, “I Stand.” What kinds of things inspire you to write?

Oh, that’s a good question. Well, I think I just kind of day-to-day write what I’m feeling. Often I just go circles with myself, trying to get out of my own head, and I’ll write about, you know, an argument I had with my husband, or a great day I had with him, or something upsetting I’m going through. And then I go in the studio and I sort of just keep myself open and do a bunch of takes, and then take what feels the most true and honest.

Does having this role in writing your songs affect how you sing them?

Well, [singing] in the recording studio is a different art form than just being on a Broadway stage, because you’re forced to be able to sing into a microphone really close and be really quiet sometimes. There are different timbres to my voice that I can accentuate when I’m in the studio that I can’t necessarily do onstage, because you have to get it to the back row. These more vulnerable qualities come through, like the fragility of the voice in my low register, which people don’t necessarily know I’m capable of doing, because it’s a lot of sensuality and a lot of authenticity in that part of my voice. And so I enjoy being in the studio because I get to show all that different color.

What has it been like touring and being on the road?

Well, it can be tough to pace yourself. You’ve got to get your sleep when you can. And I’m on a tour bus, which is really exciting for me. I’ve always wanted to get a tour bus! And [I’m] performing my original music, so this is a real dream for me this summer.

Has it been difficult to maintain a relationship with your husband, since you both have very busy, successful careers?

It’s hard work when you’re in different cities all the time, but we’re figuring it out. We try not to let more than two weeks go by without us seeing each other. And he’s gonna come visit me in North Carolina next weekend, and I did the rounds a couple of weeks ago. Just in the middle of the night I booked a flight; I realized I had two days off, so I went from New York to L.A. You have to just do those things for each other, you have to just keep each other in your heart, and make the marriage a priority.

Have you ever battled stage fright when performing live?

Yes. Well, I don’t get stage fright to the point that I’m not going to go out onstage. I do have nerves, I do get nervous, it’s just that I try to use it as a good adrenaline, a good nervousness, and channel it into my performances. I think when people look at their nerves as the enemy, it gets worse. But if you just assume you’re going to have nerves, and try to breathe, and incorporate it and be honest about it, it helps.

Do you have any pre-performance rituals?

Yeah, I always take a very steamy shower, and I warm up my voice for a half hour, and well that’s my main thing, always taking the steamy shower and warming up, doing my vocal exercises and everything.

It was announced this week that there is talk of a movie version in “Wicked” that’s in the works. Would you be interested in doing that?

Of course I would. I just think that’s further away than people think, so I don’t know if I’ll be right for it by the time it actually goes into production. [laughs] But of course I’d love to do the role again. But I’ve been lucky enough to get to do that with “Rent,” and I think that once is probably pretty special!

You just completed a workshop of “Nero” Would you be interested in staying with that if it goes on?

Yeah, that was with Duncan Sheik and Steven Satar; they did “Spring Awakening” It’s just in the early stages now; it’s something they’re still working on. But yeah, I’d be very interested. It was really a great collaboration, hanging out with them? we really got along great. But we’ll see what happens. These things take a long time to develop.

A large group of your fans recently sent you a special birthday present. What was it?

Yeah, my fans are pretty amazing. They’re so loyal, and they’re very supportive. And as much as they love to hear the songs from certain shows, they’re so supportive and enthusiastic about my new music, and they sing the lyrics to my new songs at the concerts. And, you know, I’m very indebted to them, because a lot of people try to pigeonhole you and make you be one thing, and they’re very open to me being versatile and embracing that about me, and I appreciate it. And my song “I Stand,” that’s about a personal experience I was having one day. I never expected it to inspire this wonderful video they sent me for my birthday, where they all cut together these pieces of them holding up signs about what they stand up for. It’s really powerful.

Idina Menzel comes to The National at 8 p.m. on Wednesday, July 23. Tickets are $20-$35. 612-1900.