In ‘If I Stay’ (opening Friday), Chloe Grace Moretz plays Mia Hall, a superbly talented young cellist who dreams of graduating from her Oregon high school and traveling east to study at The Juilliard School. Based on the best-selling novel by Gayle Forman, “If I Stay” traces Mia’s journey after an accident puts her into a coma that has her on the brink between life and death. Things are further complicated by Mia’s newfound first love with a young rock ‘n’ roller.

Q: I’m sure there were many challenges with this role, but what was the biggest one for you?
A: I think the biggest one for me was realistically capturing that first love aspect of the story. People can create characters who suffer loss, and emoting loss is very easy for me. So emoting the happiness and the pure elation that comes from the first love and cute little flirty moments that my character Mia and Adam [played by Jamie Blackley] have was hard. We had to make it realistic. We became friends, Jamie and I, so that made it easier.

Q: Did you actually learn how to play the cello for this film?
A: I had a great teacher and some great doubles who really played the complicated parts, and stuff like that. But I did train for about seven months on the cello before we started filming. It was intense. Everywhere I went during the year prior to the beginning of filming on “If I Stay,” there was a cello there. No matter what movies I was working on, I’d arrive and a cello would be there. I worked hard, but honestly it was less of the making it look perfect with the finger holds and things like that. It was more, for me, being comfortable with an instrument like that — something that is very intimate the way you hold it. Especially for a girl, performing in a dress, and this big thing is there and the way you have to hold it. It’s like this gigantic, intimate instrument. When you see a cellist play you almost think of it as a wind instrument because they breathe through their bow strokes. There is an energy that cellists have when they play, and I really wanted to capture that.

Q: Do you listen to and appreciate classical music differently now that you’ve played this role?
A: I’ve always appreciated it, but when I found out how hard it is to play these instruments, it made me appreciate it more. It’s not like the guitar or drums, which you can pick up and play relatively well if you put your mind to it. But for the cello, you need to train and practice for 15 years to even play them in a mediocre way.

Q: There’s role reversal here, too. Your parents, played by Mireille Enos and Joshua Leonard, are the liberal, former hippie punk-rockers. You are the conservative, straight-laced one. That must have been fun to play.
A: Yeah, it was fun. Mireille and Josh are so great, it was wonderful being with them. But in the film, it is unusual to have them be the ones encouraging me to go have fun, go have a boyfriend, go party! I was the one who was conservative, rigid, orderly, focused on getting into Juilliard and worried about the future.

Q: Your director, R.J. Cutler, is a well-known documentary filmmaker, but this was his first fictional feature film. Do you think his background as a documentarian helped him capture the essence of this story, which raises all kinds of real-life issues about dealing with unimaginable loss?
A: I think most of the reason he got hired is because he is a documentarian. He kept everything real and natural. He was telling the story in a way that felt kind of authentic. I think in the hands of another director, it could have become very sci-fi — a movie about what it all means, “traveling to the other world,'” going to “the other side,” stuff like that.
Instead, he is so naturalistic, he brought a gravitas to it.

Q: How much of yourself — you as Chloe — did you bring to creating the character of Mia?
A: I think the goofiness is a key thing I brought to the role of Mia. She’s a lot cooler than I am. She’s so calm and collected the way she was written on the page. I think I added those goofy moments, which are more like I’d act in similar situations — if they happened to me in real life.