Sentence:  A biting , pithy parable of the all pervading <WSD>hollowness</WSD> of modern life , the piece has been set by Mlle Lagoon to a sumptuous score ( a single motif played over and over by four thousand French horns ) by existentialist hot-shot Jean-Paul Sartre . 
Meaning of the word marked with <WSD> tags:  the state of being hollow: having an empty space within