Those two Gershwin brothers wrote "'S Wonderful!" for a musical, I think it was Porgy and Bess. Anyway, this song is such a perfect example of a verse refrain it should be in the dictionary. It starts with a nice little four bar piano intro, and then it goes to the verse, which starts at measure five and lasts until measure twenty nine, when the refrain starts. The refrain begins with the chorus, which goes from measures 29-32, and then the bridge from measures 43-52, then its the chorus again until the end. The refrain is significantly more stable harmonically, it has a slower harmonic rhythm than the verse. The verse also uses a lot more nondiatonic chords than the refrain does. It really works for the verse to be more harmonically unstable, because that's where the interest is. In the verse the melody itself is really boring, so the chord changes under the stable notes keep the listener hooked. In the opening section a falling fifths sequence is used, often it is only the latter half of the first of the two bar pair, so don't let that fool you. There's still falling fifths in there, you just have to look for them. That was a good choice in those falling fifths, they are always popular. So remember how I said that the refrain has a more boring harmony than the verse? Well, that doesn't mean that it's one hundred percent boring. For instance, in measures 31 and 32 (and 39 and 40) George writes a C# diminished chord, which is used to embellish the word "marvelous". The word is held on a single note in the vocal part, so to add interest there is a fun little chord progression with the c# dim to a c chord back to a c # dim, just to keep you interested. Then he used a Bb add 6 chord in measures 33 and 34, under the words "you should care for me", which is what IS so wonderful and so marvelous in the song, so it's kind of the point of the song. It needs some emphasis, because it is the whole reason for singing the song. The added sixth chord is saying "HEY! hey you! listening to this song! this is the point" Then Gershwin gets really funky, he decided to randomly go to G major. I know, it sounds crazy right? Well, George was man. So crazy. So there he is, chilling out in G major in measures 44-48, and he goes ii, I64, V42, vi 43, V7. So this is when the words are going "You've made my life so glamorous" and "My dear, it's four lear clover time". These are really happy words. I mean, the whole song is pretty happy, but these words aren't even like "oh it used to suck but now" instead these words are totally focused on the awesomeness that is now. So I guess George thought that to really emphasize this glee, he should put it in an even happier key. So he did. Ok last question! So he uses that e minor chord in measure 47, and it's crazy because the piece is in E flat major and then all the sudden it's an e minor chord. But he harmonizes it as a vi of the G major section, and keeps that crazy E natural out of the bass line. That would really mess the listener up so George wanted to prevent that. All in all, I think that George was a pretty fabulous writer, although I have questions about Ira. Who has ever said to their significant other "You've made my life so glamorous?" or "My dear, it's four leaf clover time". I don't think those are very good love song lyrics.