0 Diegetic music in a film or TV programme is part of the action and can be heard by the characters, rather than being just for the people watching to hear:
The music works to position us in terms of this diegetic containment.
Thus even a solo performance is a type of montage, a combination of mimetic immediacy and diegetic distancing, a composite of dissected realities.
Instead, it seems to have split into a number of 'diegetic' musics that emanate from performers within the fictional world of the drama.
Given its diegetic context and its potentially maudlin terms, the vehemence of the chorus' expression struck us as noteworthy.
That is to say, music is not so much source (diegetic), background (non-diegetic), nor just mutually implicated in the narrative meaning of a scene.
The orchestral dimension, moreover, can assume the function of a frame, a necessary basis for the creation of the diegetic dimension.
The diegetic screening of the film is indicated, at first, only indirectly.
The music moves from diegetic to potentially non-diegetic spaces as he goes outside to catch a bus.