Frank Cope was probably the world's first bona fide disk jockey.  His daily five to eight a.m. "Alarm Klok Klub" on KJBS was San Francisco's most popular radio program for nearly twenty five years.  He joined the station in 1930 and except for a short haitus in the early 30's he was a fixture of San Francisco radio until 1959.   The photo above is from 1931;  the one below was taken in 1954.