Boston classical music station WCRB has leveraged a partnership with the Boston Conservatory to compose a new branding tool: a musical logo. The station opened a contest for Conservatory students in the spring of 2014. Out of 18 entries, WCRB staff chose a 6-second sonic logo, or “sounder,” submitted by Paul Fake to be its new trademark sound. Fake, 27, lives in the Boston area and composes concert music. “What you look for in a sounder is something that won’t become annoying or repetitive,” said WCRB Station Manager Tony Rudel, who initiated the project.