When you film a conversation, you can film it two ways.
You can film the scene with a single shot showing both actors talking. If you do, there is absolutely no way to add gaps between the sentences of the dialog. Don't do this if you want to have a narrative film score in the middle of the conversation.
You can film the scene from multiple camera angles so that you only see the mouth of one of the actors at a time. This is currently the way more serious conversations are filmed. Therefore, there is nothing special you have to ask the director for. It will be provided for you.
The scenes of "Blindman's Bluff Production"
As you might guess, the scenes that are on this disk were filmed in the traditional way with lots of coverage. Therefore, the footage is ideal for adding narrative dialog by adding gaps between the sentences of the actor's dialog.
In both scenes, the actors talk back and forth like a ping pong match.
As soon as one actors is finished, the next actor starts. This natural rhythm continues through the entire conversation.
Editing without narrative music
When you edit a conversation, you use this natural rhythm when you edit. Probably, you will use the exact same pause between the words of the different actors in your edit. Even though you will take the audio from different shots, the audio will be combined to sound exactly like the original conversation. There will be only a tiny gap between the words of one actor and the words of the other actor.
This will sound perfectly natural. No one will be able to tell that the dialog came from different shots.
When you watch one person listening to someone else speaking, you have no idea who who is talking. The facial expression of the actor does not tell the audience who is talking.
Therefore, when you add narrative music in the middle of a conversation, you show someone listening. The audience will not know if the music is talking or another actor is talking.
Not complicated
This sounds extremely complicated but it is surprisingly easy. You do not need to add cut away shots or anything.
The normal way
If you edit a scene without adding narrative music, your first step is to edit together all of the pieces of the conversation. That is, you edit together all the audio.
Example
If you have two people talking back and forth, you might start with the establishing shot for the first actor's dialog. Then you will cut to an over the shoulder shot for the second actor's dialog. Then you cut to an over-the-shoulder shot of the other actor talking. You will do this back and forth. Finally, you begin cutting back and forth with the close up shots. Finally you end the scene by cutting to the establishing shot for the final actor's dialog.
Separate tracks
When you edit the scene this way, it is much easier if you put the different actor's dialog in different tracks. This makes adding the gaps so much easier.
Figure out the music
Before you add gaps for the narrative music, you need to have the narrative music. That is why the film editor should also be the film composer.
In both scenes, the actors talk back and forth like a ping pong match.
As soon as one actors is finished, the next actor starts. This natural rhythm continues through the entire conversation.
Editing without narrative music
When you edit a conversation, you use this natural rhythm when you edit. Probably, you will use the exact same pause between the words of the different actors in your edit. Even though you will take the audio from different shots, the audio will be combined to sound exactly like the original conversation. There will be only a tiny gap between the words of one actor and the words of the other actor.
This will sound perfectly natural. No one will be able to tell that the dialog came from different shots.