The sixth installment of the hugely successful Live Lounge series may contain such heavyweights as Adele, Take That, and Avril Lavigne, but scan the track list and one particular name is likely to spark the most intrigue. The first time Leona Lewis appeared on the BBC Radio 1 mid-morning show, her epic orchestral reworking of Snow Patrol's "Run" was so well received that it not only went on to reach number one in the U.K., but also became perhaps the defining moment of the Live Lounge's ten-year history. Her equally string-soaked rendition of Labrinth's shimmering R&B hit "Let the Sunshine In" appears to be aiming for the same kind of result, but falls far short, partly because the original isn't anywhere near as strong, and partly because, like her second trip to Maida Vale Studios (where she performed Oasis' "Stop Crying Your Heart Out" in a similar manner), she's starting to feel like a bit of a one-trick pony. It's a problem that encompasses this 40-track collection now that the element of surprise has gone. Indeed, where it used to be something of a novelty to see credible guitar bands covering pure pop songs, now you don't bat an eyelid when you hear the likes of Vampire Weekend transferring their Afro-beat sensibilities to Cheryl Cole's "Fight for This Love," Everything Everything turning Rihanna's "What's My Name?" into an angular slice of indie funk, or the Vaccines transforming Katy Perry's party anthem "Last Friday Night" into something altogether more doom-laden. Indeed, for perhaps the first time since the compilation series began in 2006, it's the artists' performances of their own material that prove to be the most compelling. Kosheen's Sian Evans blows everyone else out of the water with her stunning acoustic take of her number one collaboration with DJ Fresh, "Louder"; Magnetic Man prove that dubstep can work in a live setting with the slightly sinister robotics of "The Bug"; while Plan B showcases his soul-man credentials on a stunning stripped-back version of "Love Goes Down." Like its previous releases, Live Lounge, Vol. 6 is unavoidably a hit-and-miss affair, but while there are still several flashes of inspiration on offer, there are also signs that the whole concept is beginning to run out of mileage.