This video of Slovakian violist Lukas Kmit improvising around Nokia's signature ringtone is so good, many have thought it was a sly piece of advertising for the Finnish telecommunications giant.

But, as it turns out, it's 100% the real deal, with the classical fiddler - our term - interrupted mid-performance by an inconsiderate mobile phone owner before taking the tune and playing it on the viola himself.

Classy, clever and ever-so-witty, it's probably the most popular YouTube video involving classical music for years. Unless you count dogs barking Star Wars' The Imperial March as classical music, in which case, since last week.

It should be remembered that the Nokia ringtone - also known as Gran Vals - is actually a piece of classical music itself, originally written by Spanish classical guitarist Francisco Tarrega in 1902. As any die-hard QI viewer already knows, of course...

But it's not the first time someone's taken the ubiquitous and highly-irritating ringtone and turned it into something far more beautiful - as this, the Cell Phone Waltz by harmonica virtuoso Jacob Venndt, emphatically proves.