Meshes of the Afternoon

Maya Deren's shows a theme well through the method of surprise and repetition. Such distinction is reinforced gradually and has the powerful effect in the sequency of the third self being. (It'd better analyze one sequence, not one scene because this movie has the unique structure and subject according to it of each self being.)
The third self sits down the table which other two beings already sat on. As soon as she puts her knife on the table, it changes into the key with the sound of the drum. Sound in this part stirs up the tension and emphasizes the reversal paralleled with transition of the shots. During the course of two self-beings' taking the key, sound-tempo and timber of the pipe and drum- is almost same and has regular pattern. But the stark sound is heard at the moment the third picks up the key and turns her hand inside with the visual stimulus, colored palm and knife changed from the key. Sound at this point makes suddenly frightening mood.
Editing of this sequence is remarkable. Maya often uses trick though the editing to express the free shift of time and space. The key continues to still be shown in the middle of the table after two self-beings' grabbing it. Furthermore, when third being goes forward the real-being taking a nap, the shots of the walking foot destruct the continuity of the space as jump cuts and are punctuated as the expansion and the transition of the dimension.
The tense as self-being in the dream goes to the real being sleeping in the real world is rising up and the shocking turning point happens through the change of POV. Before she wakes up, POV in the scene is her self-being in the dream. But after she awakens by the knife approaching to her, POV is her real-being in the present. There is the connection between them. The former sees her and the latter does her husband. The interesting is that there is the knife shot between them.
And as soon as she sees her husband, she cover her sight with her hand. It makes us guess the knife has some relationship with her husband.
Even though this movie has the different form and style unlike the conventional movie, it offers hints to figure out the message and effect the director intends.
And we can share it by analyzing sound, editing and transiton of POV in the sequence goes toward the climax.

The Conversation

The Conversation [Francis Ford Coppola] depicts the downward spiral of Harry Caul [Gene Hackman], who is a covert surveillance expert and private investigator, as his paranoia causes him to get drawn into an elaborate and confusing murder plot. Harry Caul [Gene Hackman] and Stan [Johnny Cazale] are in the workshop editing the surveillance audio from the day prior. Multiple aspects of this scene build up the characteristics that are vital to driving home the overarching significance of what is about to transpire in upcoming scenes to make the movie effective on the whole.
Walter Murch [Sound Editor] and Howard Beals [Sound Effects Editor] managed to edit the audio so that it illustrates exactly what is going on in this scene, and the rest of the movie. Harry begins to his editing session by listening to the raw audio. The audience hears this as a bit of the targeted source audio (the couple) and a lot of background noise. Eventually, as the couple walks in front of a street drummer, you here nothing but the drummer, which prevents Harry from hearing something that may be important. Harry must filter out the garbage audio. He rewinds, you hear the rewinding effects, and plays again while playing with an envelope filter. You hear the audio change as he messes with the faders and knobs of the filter he invented.
This helps communicate to the audience what he is physically doing with the sound without ever taking the time to have the character make an aside and say, “I am doing this right now for this reason.” Harry Caul, as a deeply secretive and introverted person, would never say such a thing to anyone. This character trait is held sturdy throughout the movie and is reinforced again in this scene. There is nothing stopping him from explaining this to Stan, who is curious about what Harry is doing. It is only that Harry Caul is overly protective of his secrets and this builds his character.