Like such groups as the Three Tenors and the Three Graces, the 2Cellos mix classical crossover with good looks and a prime number in their name to create an excitement for music that fills halls with young fans.

But in addition to playing Vivaldi and Bach, the two Croatians — Luka Sulic, 28, and Stjepan Hauser, 29 — have created vivid cello-only versions of songs made famous by acts as unexpected as Michael Jackson and AC/DC.

Viral videos of that approach (their version of “Smooth Criminal” has been seen more than 17 million times since 2011, and their 2014 “Thunderstruck” nearly 54 million) landed the duo on a tour with Elton John, who said: “I can’t remember seeing anything as exciting as them since I saw Jimi Hendrix live back in the ‘60s.” Now Sulic and Hauser are on their biggest U.S. tour yet.

The Washington Post talked recently with Sulic from the road in Atlanta.

Q: How many musicians are with you onstage?

A: The first half of the show is only the two of us. The second half, we add our drummer and it becomes a rock show at that point. It’s basically a journey that starts like angels and ends as devils.

Q: Has classical music always been part of your approach?

A: When we grew up, we were classically trained. I started when I was 5 years old. … But at some point, we wanted to do something different, do our own arrangements and attract young people to this great instrument. When you play only classical music, you’re playing notes that have been there for a few hundred years. We wanted something that was newer.

Q: When did you two meet?

A: When we were around 14. We are from the same country, and there are not many cellists there. So we met at a summer music camp — young, talented kids playing the cello. We were practicing like crazy. But we were sort of rivals, too, since we went to the same competitions and the same music camps. … But we were always great friends if we did something together. … We wanted to make a revolution — not only a personal revolution. It was a rebellion that drove us to make this project. It became our way of life.

Q: Success happened rather quickly, didn’t it?

A: The first song we did together, “Smooth Criminal,” it exploded straight away. We didn’t expect it would be so big from one song. But millions of kids watched it on YouTube, and then people started calling from all the TV shows — “Ellen DeGeneres” and “The Tonight Show.” Then record labels started being interested, and Elton John picked up on the song, invited us on tour and took us under his wing. We opened for him everywhere. Which was such an amazing experience. Then all the hard work began.

Q: What is it about the cello that makes it amenable to rock?

A: The cello is such a versatile instrument, just about anything can sound good — except for rap. We still haven’t learned how to do rap on the cello. But rock music and metal are great because it’s so powerful. But a cello can be beautiful melodically, which makes it perfect for film music and classical music. Because of its range, in cello you can do everything. It has colors similar to a human voice.

Q: How did you arrive at Michael Jackson’s “Smooth Criminal” as the song that would initially define you two?

A: We were in London, thinking of ideas, and were both big fans of Michael Jackson, wondering what we should do. Then we thought of “Smooth Criminal” because it would sound so cool on cello — that chk-ka-ka-ka-ka in the start of it. So we went back to Croatia and rented a cheap studio for $100 for a full day and had the song finished. We did the arrangement when I was in London finishing studies, we Skyped together to practice and went to studio and did the audio recording. Then we made a video for $1,000 from a videographer who gave us a discount — we split the cost, $500 each — and it changed our life, with such little investment.

Q: What came next?

A: “Welcome to the Jungle” was the second video, and it was a great step up toward more rock. Then we dropped our first album on Sony Masterworks, which sold well. But we didn’t continue making as many videos as we should. We went on the road with Elton John and didn’t have time to build our YouTube fan base. So later, when we realized that, we filmed “Thunderstruck,” which was a bigger hit than “Smooth Criminal” and took us a step higher. We started doing what we wanted, took charge of our own career, went back to our roots and started making more videos. Since then, it’s been going even better, and we try to record as many live concerts as possible.

Q: Are you seeing a lot of young people in your audience as a result?

A: Our fan base is so diverse. We have rock fans, classical music fans and crossover fans. … We see a lot of aspiring musicians in the audience. We get fan mail every day from kids who aspire to play. In Croatia, there are not enough cello teachers or cellos in music school because of what we did.

Q: Have you heard from any of the acts whose songs you have used, like AC/DC?

A: Actually, one day before our fifth anniversary, they shared our video of “Thunderstruck” on their official Facebook page. Nirvana, Guns N’ Roses and Iron Maiden, all of their official Facebook pages have shared our videos. The Jimi Hendrix page shared our “Purple Haze” live video.

Q: What was it like touring with Elton John?

A: We did a 20-minute set before every show for two years, then joined him for half of his set with his band when he needed strings. It was an amazing experience. We played in such big venues. We really got to learn from the best how to be a performer. We got this experience playing for large crowds so that it was much easier for us to do it when it came time for us to headline. It was really valuable.

Q: Does the classical community look down on you for playing pop music?

A: Not really. Any classical person who can play an instrument can see what kind of level we’re at. We’ve got a very good history as classical musicians and individually have won a lot of competitions. There are people who prefer classical music; they don’t like rock music or metal, which is OK. But they can’t say anything bad about our playing or our art of arranging a song.

Q: Do you feel you’re introducing young pop fans to classical music?

A: From many of our fans, we get feedback like, “I never thought classical music could be beautiful,” and they begin to appreciate classical music as much they do popular music. And we include classical songs in the concerts.

Here and there, we do concerts with only classical music, or only film music, which we’re going to share though YouTube, so we’re not only playing for a few hundred people in the audience, but sharing it through the Internet. Also, the choice of pieces have to appeal if you want to reach a lot of people. The problem with classical music, as in each genre: It has good music and bad music, and you cannot reach a huge audience with music that isn’t interesting and special. You also have to present it in a special way, educate them about what’s special about the music and share it on social media. It’s about opening up to the world and sharing the beauty of the music.