Playing music outside is like playing to the ocean, local musician Kate Gaffney said. "If you're standing near the ocean, anything that's ever bothering you, you can just toss it out into the sea, and the sea will just engulf it and you won't have to worry about it again." On Friday, the Philadelphia-native singer/songwriter will be headlining Concerts in the Park. Opening for Gaffney are Boulevard Park, West of Next and Christopher Fairman & The Stilts (click on links for MySpace). Gaffney first visited California during a college internship, instantly deciding it was the place for her. After earning her bachelor's degree from Penn State, she moved here and took a job at Sacramento Coun