Ladd's devotion to the music earned him an invitation from Pink Floyd’s Roger Waters to be a part of his 1987 album "Radio K.A.O.S." Ladd played himself as a rebel disc jockey on the recording.

Longtime disc jockey Jim Ladd, a central figure in the emergence of FM rock radio in Los Angeles, died Saturday after a heart attack. He was 75. Ladd’s death was announced Monday by Meg Griffin ...