m. 13: V7
m. 15: I V6 vi6
m. 16: V7/V Vadd6 ii43
m. 17: I64 V I
The structure of this piece follows the form aaba, or quaternary form. This song has a simple chordal progression, and the "a" and "b" sections mainly differ because of rhythm. The difference is not extremely significant because the B section still has that flowing quality to it. In addition, it ends on a half cadence. The new harmony that is apparent in this piece is the Vadd6 chord. I really like the placement of this chord in measure 16. Foster places it in the second half of the second beat, then has a pause, which then leads to the final cadence of the song. This formation definitely emphasizes the jazz sound of that unique chord.
If I were to perform this, I would make sure to place a lot of emphasis on dynamics due to the simplicity of the song. I would also try to give it as much as a flowing and light-heardted feeling.