How millions of YouTube hits and a phone call from Elton John rocketed two classically trained cellists to stardom.

Croatia’s got talent. And two childhood friends from Zagreb, Luka Sulic and Stjepan Hauser, have set out with their cellos on their backs to show the world just how far raw talent can take you in the age of YouTube.

The pair, playing together as 2Cellos, boasts serious classical credentials: Sulic studied at London’s Royal Academy of Music and has given concerts at Wigmore Hall; Hauser has racked up 21 first prizes in international cello competitions and includes two performances for Prince Charles among his career highlights.

But it was with a video of their two-cello arrangement of Michael Jackson’s Smooth Criminalthat the boys found fame: within days of its appearance on YouTube, their self-made clip had gone viral. Sony Masterworks came calling; then, out of the blue, so did Elton John.

“After he saw the video he phoned us personally,” Sulic recalls in thickly accented cantabileEnglish when we meet at the harbour-view Sydney hotel where he and Hauser are staying. “He said he loved the video as well as our classical performances, and invited us to tour with him.”