Ferdia Walsh-Peelo and Mark McKenna say ‘Sing Street’ the band is still a possibility

The stars of John Carney’s coming-of-age musical comedy “Sing Street” have been on U.S. soil for just about 24-hours and they’re already envisioning the American dream: Going viral.

“I was thinking we should hop on a bus or the subway and start playing,” says Ferdia Walsh-Peelo, who plays Connor “Cosmo” Lalor, the lovesick Irish teenager at the center of the film. The 16-year-old Dublin native and his 19-year-old co-star Mark McKenna, who plays music protege Eamon, also filmed themselves playing a song from the soundtrack (“Beautiful Sea”) on acoustic guitars on the Mass. Ave Bridge for Instagram.

Walsh-Peelo and McKenna’s viral video scheme is rather fitting as Cosmo plots to win over his dream girl (Lucy Boynton) by making her the centerpiece of his homemade music videos. The film is loosely based on Carney’s (“Once,” “Begin Again”) teenage introduction of rock and roll in the ‘80s via late older brother, Jim. It follows the director’s winning formula of angst-twanged love, wish fulfillment and a mind-numbingly catchy soundtrack.

They chat over Cokes at the Eliot Hotel in Back Bay about the film, keeping the “Sing Street” band together and a John Carney-‘80s education.

There was the expectation that you would not only be able to act, but also be able to play a large range of music to take on these roles. What did you perform when you were going through the audition process?

FW: I sang “Blackbird” and I think it really helped a lot that I didn’t go in and sing “Falling Slowly.” John said so many people thought it was such a good idea but he’s heard that song like a million times.

MM: I did an acoustic version of “Chocolate” by the 1975. It’s a song about drugs so it was pretty funny.

In addition to the videos on Instagram, you’ve performed songs from the soundtrack as a duo while promoting the movie — like at Sundance. Are there any plans to keep the band going?

FW: Mark and I play good songs and we’ve thought about it, but we don’t want to push it. John is not going to us, “If you want to do this band thing, we’ll get you a record deal and we’ll pay for everything.” Instead he’s like, “If it happens it happens.” We don’t want to be some kind of Louis Walsh boy band thing, reminding people we’re from the movie “Sing Street.”

MM: We don’t want to be like 10 years down the line, with long beards, still singing “Drive It Like You Stole It”…

FW: While crying. [Laughs]

The film takes place in Dublin in the‘80s, years before either of you were born, what did you have to research and learn before diving in? Did John make you any required listening playlists?

FW: He sent me over loads of music videos from the ’80s because that’s a really good place to learn from; they have the fashion and the vibe and the sound and the movements. Just watching Talking Heads and the Cure, a lot of that is hugely influential in the performances that we’re doing. It was a huge learning curve for all of us, especially me because I hadn’t discovered‘80s music yet. Except Mark, he was already the master.

MM: I was already really into the ’80s already, so when John would be like, “Mark, you should look up this band,” I’d be like, “John I already know that band.” [Laughs] Or “Mark, you should watch this John Hughes film,” I’d be like, “John, that’s myfavoriteJohn Hughes film.”

Even though it’s decades ago, are there any major differences in growing up as a teenager in Ireland versus America that still ring true?

FW: What you see in “Sing Street” is pretty similar [to growing up now in Ireland], but not as violent.

MM: There areas in Ireland that can still be quite rough, but the school wouldn’t be like that now.

FW: I went to a rough area in school but I somehow won bullies over and became great friends with them. I know I don’t seem like the type, but like in this day in age, if you play music, people just like you.

“Sing Street” opens April 15 in New York, nationwide April 29.