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 very first sounds we hear in the act are of the diegetic, 'opera-house' music off-stage, within the extended imaginary space of the action beyond the proscenium.
A priori, the terms 'diegetic music' and 'non-diegetic music' situate film music as measured against the 'diegesis'.
Consequently, within an operatic context that we have defined as essentially diegetic, narrative or mediating, stage music supplies a moment of mimesis, of pure representation.
In situations where there is an absence or paucity of diegetic sound, music has become the norm.
The music moves from diegetic to potentially non-diegetic spaces as he goes outside to catch a bus.
The diegetic screening of the film is indicated, at first, only indirectly.
The orchestral dimension, moreover, can assume the function of a frame, a necessary basis for the creation of the diegetic dimension.
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.
