British pop star Melanie Chisholm is planning a special gig to mark her upcoming 40th birthday. The Spice Girls star will reach the milestone on 12 January (14), and she has decided to celebrate her big day by putting on a show in London. Chisholm has arranged a 40th birthday concert at the Shepherd's Bush Empire in the British capital on 11 January (14), the day before the big occasion, and she is urging fans to buy tickets and join the celebrations. In a post on her Twitter.com page, she writes, "'Sporty's Forty': Melanie C live at Shepherd's Bush Empire... So I'm playing Shepherd's Bush Empire 11th Jan 2014 to celebrate my 40th! Who's coming?"