Leggy Spice! Mel C shows off an impressive pair of pins as gets set to rock London for charity

By Georgina Littlejohn

Last updated at 12:07 PM on 14th September 2011

She was the fitness fanatic that earned her name of Sporty Spice during her time as one fifth of the world's biggest girl band.

And her dedication to the gym has stood pop veteran Melanie Chisholm in good stead as she flaunted her toned legs outside a London theatre yesterday.

Melanie, also known as Mel C, looked sensational in a short black dress that set off her sexy pins to perfection and showed off the large dragon tattoo on her right calf.

She's got legs: Former Spice Girl Melanie Chisholm shows off her impressive pins as she arrives for a charity appearance in a West End show

The singer, 37, was snapped arriving at the Dominion Theatre to join cast members of We Will Rock You on stage for Children In Need at the curtain call.

Melanie joined the cast of a West End show to sing with them as part of the BBC charity's POP Goes The Musical where this week, five celebrities will make an appearance in five different West End shows to perform a song.

Special guest: Melanie poses outside the stage door at the Dominion Theatre before joining the cast of We Will Rock You on stage

This is going to be great! Melanie can't contain her excitement as she chats to fans outside

The musical is based on the songs of Queen and the band's guitarist Brian May joined Melanie on stage as they delighted the audience with renditions of 'We Will Rock You’.

The audience went wild, taking part in the infamous ‘stamps and claps’ as Melanie C’s impressive vocals were stunningly enhanced by Brian May’s signature show-stopping guitar riffs.

Let's rock! Melanie is joined on stage by Queen guitarist Brian May

Melanie said afterwards: 'I feel incredibly lucky to have been a part of ‘Pop Goes the Musical’ for this year’s BBC Children in Need. I can’t believe I had the chance to perform with the amazing cast of ‘We Will Rock You’.

'I have always been a massive Queen fan, and to have the opportunity to perform two of the band’s biggest anthems and to be joined on stage by the legendary Brian May is a dream come true! Thank you Pudsey!'

Belting it out: Melanie wows the audience with We Will Rock You

And despite getting her Spice Girl moniker wrong, May added: 'I always wanted to work with Rocky Spice! And tonight it finally happened. She is such a total pro - a delight to interact with. Thanks Mel C! You rock!'

Celebrities who have already taken to the stage for the charity event include Stacey Solomon who joined the cast of Wicked for the final song on Saturday night.

All the gang: Melanie and Brian join the cast for a photo

On Monday, Amy Winehouse's goddaughter Dionne Bromfield took to the stage to deliver a rendition of ‘Why Do Fools Fall in Love’ with the cast of Million Dollar Quartet at the Noel Coward Theatre.

Tonight, Peter Andre will be on stage at the Piccadilly theatre on Wednesday night to sing Unchained Melody and tomorrow, the Sugababes will join Mamma Mia for their rendition of Abba's Dancing Queen.