The Ukulele Orchestra of Great Britain, Leeds Town Hall

The trick is to transform something relatively easy into something dazzling and bewilderingly complex. Seeing the Ukulele Orchestra of Great Britain is like watching eight masters of close-up magic. You’re not quite sure where to look, unable to believe quite what you’re hearing. These are boom times for the four-string ukulele. You can pick up a functional instrument for a tenner and learn three chords in five minutes, meaning that a huge repertoire of Western pop songs is yours for the taking. Simply strumming isn’t particularly difficult. But what the Ukulele Orchestra do is pluck, pick, slap, whistle, shout, hum and harmonise, and they do so effortlessly.

"Anarchy in the UK" is introduced as a song by the Spinners, and initially sounds like a richly harmonised slice of cheesy folk. A lengthy, sincere-sounding preamble about the English folk song collector Cecil Sharp leads into an insanely silly version of the theme from Shaft, which, as with all last night’s songs, stops before the joke runs dry. George Hinchcliffe introduces most of the numbers in a nicely relaxed, deadpan manner – he sounds like Humphrey Lyttelton and can be similarly sarcastic. He’s also funny to look at; he and Peter Brooke-Turner (who later belts out a fantastic cover of "Thunderball") can’t help raising smiles as two very tall men playing very small instruments.

Song introductions are shared between ensemble members and their banter does have an improvised, spontaneous feel, helping us forget that we’re watching them from a distance in the huge Victorian barn of Leeds Town Hall rather than a smaller venue. The sound too is excellent – just loud enough, with no trace of distortion, and there’s applause when Hinchcliffe asks us to wish their sound engineer a happy birthday. But go and hear the group for the songs, and the intricate arrangements. "Life on Mars" begins softly and sweetly, sung by bass-uke player Jonty Bankes, and slowly becomes a medley incorporating snatches of "My Way" and "Born Free". The group have a knack of starting familiar songs in unfamiliar ways, as with their take on Gnarls Barkley’s "Crazy", here sounding soft, anguished and yearning. The sole ukulele-free number, "Pinball Wizard", is transformed into an a cappella mock sea shanty. "Wuthering Heights" meets jazz and "Leaning on a Lamp Post" becomes a moody balalaika lament, as if George Formby had collaborated with the Red Army Choir. Musical humour can so easily fall painfully flat – there’s no danger of that here.

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Watch The Ukulele Orchestra of Great Britain perform "Life on Mars"