The video became a viral sensation, receiving more than 3 million views in the first two weeks. The pair was swiftly signed to Sony Masterworks, and suddenly Elton John was on the phone, inviting the two young lads from Zagreb, Croatia, to join him on a world tour.

Three years later Hauser and Sulic have played massive stadiums and prestigious shows like The Emmys and Madison Square Gardens. They have performed on Glee, and have toured the world several times both as a duo and alongside John, who is one of their biggest fans. "He is amazing," Hauser says. "He is very generous, he gave us so much support. I don't understand, why is he helping us so much? Crazy." John's enthusiasm for the band cannot be understated. "I can't remember seeing anything as exciting as them since I saw Jimi Hendrix live back in the '60s," he has said.

Hauser and Sulic have both been playing the cello since childhood, moving from their home town of Zagreb to study in Britain, Hauser graduating from the Royal Northern College of Music in Manchester and Sulic form the Royal Academy of Music in London.

As two of Croatia's top virtuoso cello players there was always competitiveness between the two, and it was when they decided to lose the competition and join forces that things really started happening for them. "We always wanted to play together," Hauser says. "There was always some tension between us and we felt that if we joined forces something crazy could happen. Because we each of us played with lots of energy and adrenalin by ourselves, and we thought, 'imagine if we played together, this would be like an explosion'. And that's what's happened."

Their first album featured cello covers of songs by Guns N' Roses, Nirvana, Muse and Nine Inch Nails. "We just wanted to rock as much as we can, that's all. Simple," Hauser says. "When it's rock we wanna rock as much as possible." Hauser is known to break quite a few strings each time he performs, and while the pair love rock music, they always include classical music in their concerts.

2Cellos' second album IN2ITION was released in January 2013, featuring vocal and instrumental guests including Steve Vai, Lang Lang and John. They have just put the finishing touches to their third album which will be released in February. "There are many weird things that happened to us," Hauser says. "But we are proud that we keep improving, that we are getting better and developing, that's what we are most proud of."

2CELLOS

When: January 8, 8pm

Where: Llewellyn Hall, Acton.

Tickets: From $75.85 available from ticketek.com.au