Chorus:

in the context of Greek tragedy, comedy or satyr plays, a homogeneous, non-individualised group of performers, who collectively comment on the dramatic action; consisting of 12-50 players, they danced, sing or speak lines in unison & wore masks.  They provided background & summary information to help the audience follow the performance; they commented on themes & demonstrated how the audience might react, the ideal spectator, giving the viewer a lyrical and musical expression of his own emotions, elevating him to the region of contemplation.  In plays, they expressed what the main characters could not say (hidden fears or secrets) or provided other characters with insight.

 

…art…before God as the supreme witness (Nietzsche):   

Nietzsche consistently argued for a mono-logical conception of art, an art that does not seek "witnesses" or an audience. Cultural & social prejudices, phobias, and pressures pervert or stunt the aesthetic/creative processes according.  The genius should be truly for himself because the dominant authorities will sedate or even steal such energies, for their own purposes and, thereby, give a trifling notion of art's true value, which for Nietzsche lies in the very "transitions of life itself."