Boston radio legend Ron Della Chiesa will discuss the life of Frank Sinatra on Wednesday at 7 p.m. at this month’s free Bathhouse Lecture. A showing of the film “Sinatra, a Man and His Music” will follow the talk. The event is sponsored by the Hull Public Library, Hull Lifesaving Museum, and the state Department of Conservation and Recreation. The Mary Jeanette Murray Bathhouse is at 204 Nantasket Ave.