It's a cliché to say it, but Sugababes have always been too cool, too credible and too damn combative for their band-name - would you ever have described Mutya Buena as "sugary" or a "babe"? It's kind of ironic, therefore, that the group's original trio of members has recently petitioned the European Trademarks Authority to snatch control of the moniker from the current and still-callow incarnation. However cringey and ill-fitting it might be, and however much the brand may been damaged by those tabloid-dissected lineup changes, it seems the name "Sugababes" still means something.

However, the group - such as it is - is now gambling its remaining cachet on a fairly radical musical reinvention. 2008's Catfights And Spotlights became the least successful LP of their career, so the girls have ditched its retropoppy stylings in favour of a more modern, danceable sound. Having inked a deal with Jay-Z's Roc Nation label, the group has recruited a palette of trendy R&B; producers - RedOne, Stargate and Fernando Garibay among them - to transform them into a sassy, streetwise urban pop outfit with one eye on the Billboard Hot 100. It's worked. With its bolshy Europop synths, club-ready beats and - gasp! - Sean Kingston cameo, Sweet 7 is as contemporary and America-friendly as a lo-cal candy bar.

In fact, each of the album's first eight songs is an uptempo club pumper in the vein of its trailer singles, the Right Said Fred-sampling 'Get Sexy', the RedOne-helmed 'About A Girl' and the fuzz-thumping 'Wear My Kiss'. Sadly, as hip and hooky as these tracks are, they're also rather characterless, with only 'Thank You For The Heartbreak' displaying the Sugababes spunk of old. Meanwhile, the smattering of slowies that conclude the record - the Tedder-esque 'Crash & Burn' and a trio of Stargate-by-numbers ballads - are utterly lacking in emotional heft. Just compare 'Sweet And Amazing', the platitude-ridden self-empowerment song here, with 2005's genuinely affecting 'Ugly' and Sweet 7's fundamental lack of distinctiveness becomes glaring.

The problem? Well, it's partly that none of the group's current constituents has the on-record charisma of a Buchanan, a Buena or a Donaghy, and partly that Sugababes have completely surrendered creative control to their producers. Group members have been involved in the songwriting process from 2000's One Touch right through to Catfights, but none of the present lot blemishes her lyric pad once for this record. Cue girls from East London, Liverpool and Aldershot telling us to "toast it up", couplets to make Mutya spit ("I'm just a pretty little thing / Who'll make you wanna sing"), and sisterhood being jettisoned entirely on the crass, misogynistic 'She's A Mess'. Sample lyric: "She's sweating bullets / I'm not impressed." It's sad to say it, but Sugababes have never suited their band-name more.