Hammerstein and the subject of dealing with change
I know he doesn't explicitly mention this theme in his lyrics, but I'm sure I could see this manifested in several different ways.
I've got this feeling that inspirational songs like You'l Never Walk Alone and Climb Every Mountain could provide strength in trying times, but I think that Hammerstein implicitly touches on this theme in other ways. Ol' Man River demonstrates how the Missisippi "keeps rollin' along" regardless of what's going on in the world. The Carousel soliloquy serves to pep Billy up for the changes that lie in store for him, even though we know he kills himself and forsakes his responsibilities. And even in Edelweiss I can see Hammerstein giving Captain von Trapp the words to sing to help his fellow countrymen remain firm in the face of the oppressive government that has overrun Austria. It feels like Hammerstein is using the Edelweiss flower to symbolise the unchanging facets of life in this rapid, ever-changing world.
Perhaps Hammerstein' demonstrates the degrading effects of change and modernity in Allegro. I know I haven't seen it or gotten acquainted with it, but perhaps it could illustrate how Hammerstein seeks to address these issues. The song Come Home could probably reflect his beliefs that the loving security of your family, friends and relations can provide you with sustenance in this fast-paced world.