It's two years since Keane released their debut album, Hopes And Fears, and since that time they've scooped countless awards, garnered a whole heap of critical praise, toured the world and performed to a global audience at Live 8 in Hyde Park. If they've been feeling the pressure to deliver a crowd-pleasing follow-up, it certainly doesn't show - Under The Iron Sea finds the band picking up where they left off with considerable ease.

Some have heralded this new album as the sound of a more progressive, experimental Keane, still brimming with poppy melodies but with a darker edge. In truth, this sophomore album marks only a minor progression in sound for the band. There's a more liberal use of texture- and atmosphere-creating effects, including the occasional metamorphosis of Tim Rice-Oxley's piano lines into the sound of an electric guitar, but Kid A this ain't. A "sinister fairytale world gone wrong" is how the band describe the album, but don't be expecting a concept piece - it's only on the instrumental Iron Sea or the poignant, damaged Broken Toys ("I guess I'm a record you're tired of / I guess we're just older now") that this claim holds true.

Elsewhere the band unveil a rockier, U2-influenced sound, as on lead single Is It Any Wonder? and the anthemic Crystal Ball. There's also further evidence of Keane's fondness for uplifting Eighties pop - the optimistic Nothing In My Way and Put It Behind You are packed with infectious energy, while Leaving So Soon sees Tom Chaplin's yoyo-ing vocals almost Aguilera-esque in their showy octave surfing.

It's not all good news, though. The dreary slow ballads Hamburg Song and Try Again are symptomatic of Under The Iron Sea's emotion-draining over-production, glossy and grandiose but lacking any sense of intimacy or candour. Likewise, the overblown, string-laden Bad Dream suffers for the band's desire to fill every last second with stadium-sized sonics.

There's little here to disquiet fans of the band, who'll find Keane's trademark chest-swelling melodies and contemplative lyricism in abundance. Those looking for an album which treads the line between mainstream pop and stimulating innovation, though, will find this a rather empty vessel.