Florence Welch has been struck down with 'acute vocal strain'
The Darkness, The Cribs, Snow Patrol and Tribes also delight fans at the Kinross-shire festival
Singer also opens up about her love of Calvin Harris
The decadent clip for the latest song to be taken from 'Ceremonials' is directed by David LaChapelle
Florence Welch will join Stevie Wonder and New Order in topping the festival bill
The track will feature on the 'Snow White And The Huntsman' soundtrack
But singer says she's pleased she's a musician rather than a 'personality'