Yonder Mountain String Band will perform Saturday night at the Somerville Theater in Somerville, MA. Dispatchs Peter Francis will open the show. Fans are encouraged to wear costumes, as a contest will be held in between sets. Several prizes including t-shirts and CDs will be awarded. Grand prize is a pair of tickets to any Gamelan Productions concert prior to the end of the year. Showtime is 7:30. It is an all ages event.