Psychoanalysis provides a language for describing the “symbolic” aspects of life; by posing deeply meaningful occurrences in the primal language of the womb, father, and mother (not to mention phalluses…), some thinkers can describe the aspects of film that seem to beg for broader interpretIons.
Marxist theory is mostly useful if your focus is a film’s mode of production and reception, or if you are concerned with labor, materiality, and commodification. The acts of composing and performing, for example. Or how marketing and selling one’s art has can change it. Sometimes Marxist analysis can be useful for understanding the revolutionary potential for art (like Attali). Truthfully, most sociology and anthropology is indebted to Marxism.
The reading for today (and last week) referenced Adorno and Eisler who were Marxists from the Frankfurt school in Germany, a group of scholars particularly interested in the effects and consequences of the “culture industry” and “mass culture.”
I hope this helps to clarify things.