By Paul Sandle PILTON England (Reuters) - Kaiser Chiefs kicked off three days of music at the Glastonbury Festival on Friday, with lead singer Ricky Wilson singing "I predict a riot" to a good natured crowd made even more amenable by a halt in the rain. The British band were the surprise opener at the event at Worthy Farm in rural southwest England, which is as famous for its mud as for its line up. "Glastonbury we are honored to kick off your weekend of fun," Wilson told revelers. The festival started in 1970, when hippies paid one pound to see acts including Marc Bolan, with free milk from the farm thrown in.