"The Astrologer"

The independently produced Craig Denney film "The Astrologer" (1976) features the marquee of the Belmont Theatre in Long Beach. It's presenting the premiere of the film-within-the-film, also called "The Astrologer." Thanks to Mark E. Hueck for spotting the theatre in the film and Eric Schaefer for getting the screenshot. 

See the page about the Fox Belmont Theatre on the Los Angeles Theatres site for many photos of the building. It opened in 1929 and was repurposed as a health club in the early 1980s.

On IMDb: "The Astrologer"