Wozzeck
Another musical technique he uses is the leitmotif, in which particular characters or things are linked to particular themes or musical ideas.  This technique can be very useful to suggest certain things.  For example, there is a leitmotif for the earrings which the Drum major has given to Marie.  When the major makes love to Marie we hear this leitmotif.  The music makes us realize that he is not forcing her to love him but that she is willing.  In another place, the military music tells us that Marie is thinking of the Drum major.