Singer joined West End musical cast during surprise encore of signature 1996 hit
Empowering single appears on Scottish singer-songwriter's sixth album 'Kin'
Singer dances heartbreak away on defiant new song off upcoming solo LP
"We want to celebrate and have a party – and when we do, you're all invited," Ginger, Baby and Scary Spice say in video, hinting at reunion
Empowering clip supports Global Goals Campaign's #WhatIReallyReallyWant movement
Singer replaces departing judge Sharon Osbourne
'The whole show is about a celebration,' says Mel B
'Call Me Maybe' singer looks up to Joni Mitchell, the Spice Girls and La Roux
Festive 'Symphony of British Music' spectacle focuses on U.K.'s main cultural export
Band will join the Who, George Michael and the Spice Girls
Performances will be available digitally after each event concludes
Pop stars expected to play two hits, including 'Wannabe'
Reliving two decades of girl power
West End show 'Viva Forever!' to be based on U.K. group's hits
Scary Spice leaks news on Australian TV