London, Mar 5: Pop diva Britney Spears surprised her fans when she kicked off her Circus tour in New Orleans by actually singing a song.

The `Toxic' singer was tipped to mime throughout the entire Circus live show, but she actually sang drippy ballad Everytime with her pre-recorded vocal track reduced to a minimum.

The 27-year-old singer kicked off her first world tour in five years with a naughty show, where she changed at least 15 costumes in the time span of 90 minutes - some of the raunchiest ever seen in a pop show, reports the Sun.

She went from PVC vamp, to nipple-tassled sex bomb, dazzled in a gold body suit and other curve-hugging outfits.

The mum-of-two even startled the 17,000 crowd with her risque antics. (ANI)