'Jeanie with the Light Brown Hair,' one of the many catchy American folk-songs by Stephen Foster is a really great example of augmented dominant chords, not to mention the subtleties of the different phrases in the quaternary form. Foster's song consists entirely of two bar phrases, which demand a lolling simplicity from the performer. It is extremely necessary that the work is not over-performed, as it was most likely intended for ameture entertainment.
Quaternary form can be described as aaba, the first a is up through measure 4, the next a through measure 6, b through measure 13, and the final chorus through until the end. One interesting thing about this quaternary form is the second 'a' which only lasts 2 bars is only a small recap of the original a secion.
The chordal analysis for measures 13-end goes as follows:
m. 13 V7
m. 14 I
m. 15 I V6 IV6-5
m. 16 V7/V Vadd6 IV6
m. 17 V64 53 I
The b section of this work is contrasted from the chorus because of two distinct characteristics. Firstly, Foster begins temporarily tonicizing V with V7/V chords that include Fi (A natural). This helps enforce the feeling of the b section, or the bridge, because we really know that V (Bb major) is not the true tonic. This further creates a desire to return to the final a chorus. Additionally, another deviation in the bridge lies in the rhythms which begin to include dotted-eigth and 16th note figures. The combination of increased rhythmic complexity, and the temporary tonicization of V through the use of Fi both are key elements in contrasting the b section from the a section in Foster's 'Jeanie with the Light Brown Hair.'
As I mentioned earlier, this song contains many elements of American folk tradition such as simple melodies, simple harmonies, and a great deal of repetition. While this work isn't entirely complex, it is important to emphasize the cool chords in each of the songs!