sentences:  Its attention to characters and their psychological makeup, rather than the plot and its through-line, foreshadow the concept musical's priority of personal expression.Following "Lady in the Dark" and throughout the course of his career, Weill favored ideas over a linear narrative.Whatever the exact origin, the growing maturation of musical theatre allowed the genre to become "a vehicle for social commentary and experimentation in form," with the concept musical at the forefront of this movement.