Here in the 21st century, we've grown accustomed to thinking a person needs an electric guitar to truly rock. But that ain't necessarily so, and 2CELLOS have just delivered definitive proof with a fairly amazing cover of AC/DC's 'Thunderstruck.'

The instrumental duo, made up of cellists Luka Sulic and Stjepan Hauser, have already impressed some people in high places: their self-titled debut album (which included their take on Guns N' Roses' 'Welcome to the Jungle') topped the U.S. classical charts, and the follow-up, 2013's 'In2ition,' also broke the Top 5 -- and featured guest appearances from Steve Vai (on a cover of 'Highway to Hell') and Elton John (who pitched in on their version of Fleetwood Mac's 'Oh Well').

"Go and see them live, because it really is astonishing!" urges John on the 2CELLOS website. "I can’t remember seeing anything as exciting as them since I saw Jimi Hendrix live back in the '60s."

An Elton John endorsement is nothing to sneeze at, but it's their cover of 'Thunderstruck' that could help 2CELLOS nab a bit of crossover success -- as of this writing, the video has racked up nearly three million views, and it's easy to see why. Not only are the 2CELLOS guys photogenic and obviously good-humored, their take on the song preserves most of its essential qualities while casting it in an entirely new -- and impressively virtuosic -- light. Check it out above, and purchase the track at iTunes.