With its combination of acoustic originals and intriguing cover versions, the Radio 1 Live Lounge albums have cleverly filled a gap in the market to become one of the most successful compilation series in recent years. Volume Four, which as always, consists of tracks recorded live for Jo Whiley's mid-morning show, is as eclectic as its predecessors, with acts as diverse as Lily Allen, Fleet Foxes, and Kelly Clarkson all stepping into the now-famous studio. Without the comfort of multiple takes and glossy production, the Live Lounge can expose artists in a way no other compilation does, and where some can surprisingly thrive, others even more surprisingly falter. Florence and the Machine, one of the most critically acclaimed artists of 2009, caterwauls through a quite painful rendition of Beyoncé's "Halo," Lady Gaga unnecessarily turns her electro-pop juggernaut "Poker Face" into a rather ropey and overblown vaudeville-style number, while Black Eyed Peas don't seem to have entirely grasped the concept, using a pre-recorded backing track on their number one "Boom Boom Pow." However, the likes of the Saturdays and Sugababes, often derided for miming, sound near-perfect on entertaining renditions of MadCon's "Beggin," and Keane's "Spiralling." While Katy Perry (MGMT's "Electric Feel"), Kasabian (Gwen Stefani's "The Sweet Escape"), and Newton Faulkner (Pixie Lott's "Mama Do") tackle songs completely outside their comfort zone without disgracing themselves too badly at all. The album doesn't quite deliver a Leona Lewis moment (her number one cover of Snow Patrol's "Run" was specifically recorded for the Live Lounge, although has strangely never appeared on its albums) but there are several impressive moments. Hot Chip's intelligent electronica transfers surprisingly well to a cover of Wiley's thumping grime hit "Wearing My Rolex," Little Boots turns JLS' "Beat Again" into a synth-heavy early-'80s pastiche, while Marmaduke Duke and Biffy Clyro, both of whom feature vocalist Simon Neil, pull off charming versions of hits by Ciara and Beyoncé, respectively. With its impressive caliber of artists and its entertaining track list, Volume Four is a consistently curious listen and is undoubtedly a welcome addition to the increasingly popular Live Lounge series.