Sugababes' Keisha Buchanan, Mutya Buena and Siobhán Donaghy join fellow singer Macy Gray at Usher's star-studded final tour show at the O2
Sugababes hit the Capital Summertime Ball! Siobhán Donaghy and Keisha Buchanan pose in edgy black outfits whilst Mutya Buena keeps it racy in thigh high leather boots
Strictly Come Dancing fans go wild as they spot Sugababes stars Siobhán Donaghy and Mutya Buena in the audience supporting bandmate Keisha Buchanan in the Christmas special
