How does Miller use structural divisions (and the lack thereof) and other dramatic techniques to accentuate the content of The Death of a Salesman?

One dramatic technique that Miller uses to enhance the
concepts of the play is music.  The flute accompanies most changes in scene and
indicates the tone.  For example, at the beginning of Act II, the optimisim felt by the
characters is paralleled by the sprightly music of the flute.  Similarly, the
introduction (and reintroductions) of Ben is accompanied by its own music, helping the
audience understand that this character is only a figment of Willy's
imagination.

Another technique is the use of minimal props
and colors.  For example, the set of the "fragile-looking" (I) house glows a weak
blue is surrounded by towering buildings that glow a reddish color.  This color
represents strife and anger and threatens to beat through the weak serenity (represented
by the color blue) of the home and family.  Frequently, significant, symbolic objects
are focused upon for the audience's benefit, such as the rubber hose on the gas furnace
and the stockings that Linda continually mends.  These items are highlighted in the
stage directions during times of optimism for the family to seemingly remind the viewers
that all is not going to turn out well.