There is a slow piano section in Rhapsody in Blue which I find very interesting. It is nothing but dominant chords. You remember what those are, right? This section of music has a bass line that descends chromatically (a half step at a time.) Also, the third section is the same as the first. But for some reason they sound different. Maybe it is because one is at the beginning, and one is at the end.
The Write Stuff 