When “American Idiot” comes to the Boston Opera House for five shows this weekend, a crowd of friends and family will turn out to see Duxbury’s Mariah MacFarlane. “I was telling people my dad sort of bought out everything, so if they need tickets they have to see him,” she says. The 22-year-old Emerson College graduate plays Heather in the touring company of the Broadway musical drawn from on the album of the same name by Green Day. She’s looking forward to getting back to her boyfriend and apartment in Boston, if only for a few days. She talked to the Globe last weekend by phone from a tour stop in Detroit.
Q. Your dad was your drama teacher. How was that?
A. My dad [was] the head of the theater department at Duxbury High School for my entire life, and therefore my director when I was growing up. I would do shows every year, any opportunity I got to be in a play. We would talk about it on the drive to school. Pretty often we would have conversations about scenes and what we could do. He’s definitely a big contributing factor to why I’m at the position I’m at right now.
Q. You were still at Emerson when “American Idiot” came your way?
A. I came onto the show about a week and a half after I graduated [in May 2013]. I actually learned the whole show in three days. I went for a long weekend, three days of rehearsal in New York with the associate director and the original choreographer and a piano player. I didn’t have anybody else to learn it with, and then [after graduation] I went to San Jose, Calif., and got thrown into a full cast of 20 people and had to put what I’d learned in three days onstage. It took a while.
Q. Tell us about Heather.
A. Heather is, I like to say, the not-so-talked-about all-American girl. She is the all-American girl, it’s just not the glamorous story it usually is. She lives the life of getting pregnant at a young age and then trying to make it work with this boy from high school. They love each other, but they’re too young, and she has to grow up very quickly and make decisions not only for herself but also for a baby. And as much as I can’t relate to her having a baby, I just love her character. She makes these decisions, and then she lives with them.
Q. Pretty quickly after you started with the show, it was off to Asia?
A. We made it out to Japan, a 14-hour flight, and we were there for two weeks. Then we came back for a week, and then we went back out to South Korea for three weeks. It was brutal. Jet lag and performing do not go together so well. The Japanese as an audience in general are very polite. They don’t clap until the end, and they don’t laugh as much as American audiences. They don’t like to interrupt the performance. So I was adjusting to my first performances where the audience was silent. You sort of have to figure out how that feels. And it was the first time I’ve played houses of 3,000 people in my life. It was really cool. They sort of looked at us like rock stars a little bit. We had a lot of fan mail and a lot of gifts and a lot of people waiting outside every day before and after the show.
Q. This seems like an especially challenging show physically.
A. It definitely is very taxing. You have to plan how it is in your body. Today we have a two-show day in Detroit and we had one last night. So you’re tired and you really have to know how to do it the same every day. You can injure yourself so easily, vocally and physically. It’s a very specific show, even though it looks pretty chaotic. That’s sort of the goal, to have it look chaotic to the audience, but for us we have to know exactly what we’re doing. Inches can make the difference.
Q. You have to take care of yourself?
A. I know my voice very well, and you’ve got to know how much sleep you need, and just a lot of tricks. Here it’s so freezing cold I have a personal humidifier in my dressing room. You have to know what you can eat before a show and what you can’t. I learned that lesson the hard way. There’s so much jumping and thrashing around that you have to be so careful of what you pick to eat, because you will pay for it.
A. Do not eat an entire pizza before a show. Don’t do that.
Q. How long will this go on for you?
A. May 25, in Denver, we close the show. You never know. Every time you think a show is done, sometimes it’s not done. If I got an offer, I would definitely consider another year. I love this show a lot, so it wouldn’t be too hard to say yes again.