The core message of Thornton Wilders play, like many of his works, is housed in a metaphor - the small New England town, where life runs its course, for good or ill, as most lives do - without high drama or fantastic events. In the end when he delivers his message through Emily's final speech, it is this: to take life, in all of its smallest moments and to understand that these are what are most precious - and to not take any of it for granted. Wilder was a gentle but honest and straight forward playwright, and this may seem to be an old fashioned play, but the Copeland music is a beautiful and fitting accompaniment to Wilder's simple and heartfelt homage to what life is for - to be lived.
I suppose as someone who grew up in New England, I feel a certan affinity for this play,and must confess my bias. However, I think if you view it in the context I have explained, you may find this a really wonderful experience. If you can get a good copy with the music and dialogue clear, then it will be worth it. Otherwise, I suggest you get a copy of the more recent version of it.