Mutya Buena was more than just one-third of the Sugababes; she was their resident "attitude". Since her departure in 2005, the group have ploughed on with a carbon-copy replacement, but seem deflated without their steely-voiced tough girl. As for Buena, she appears to be thriving as a free agent: there has been a duet with George Michael, and next is a solo album with contributions from Amy Winehouse and Groove Armada. But one thing was disappointingly evident from her first solo show - Mutya minus Keisha and Heidi equals a slightly featureless addition to the queue of soloists aiming to make their mark in urban pop.

The indie surrounds of the Borderline could have been the wrong place for her, or it may be she has yet to find a way of magnifying her personality to fill the space formerly occupied by two other people. Maybe it was just the songs, few of which were a patch on the frosty brilliance of the Sugababes' catalogue. Whatever the problem, she seemed more understudy than leading lady, working through slices of her album, Real Girl, efficiently, but with little X in the factor.

This was her chance to slay the crowd and implant the Buena brand, so where was the streetwise chat? At the very least, some of us would have liked to know why she chose the Kooks' Naive for the set's mandatory cover version. No explanation from Buena, though, who was either too cool to talk to her public, or afraid to do so in case it seemed she cared.

It must be challenging to be 21 years old and in charge of a band of session musicians who have no personal investment in your new songs. But Buena has eight years' experience under her belt, and a good, penetrating voice at her command, so should be equal to a fair bit more than 35 minutes of lustreless R&B balladry.