This first movement is the unvariated portion of the Goldberg Variations. Here we have a simple case of binary form, with two distinct sections separated by repeats. This piece especially seems closed as we have the end of the first section modulating to the dominant key, and the second section taking the parallel minor key and then returning it to the original key. This piece is in G, changes to D Major, from there goes to e-minor and finally resolves back in G major. Our A section is made up of two periods each symmetrical. The first one contrasting, the antecedent phrases ending with a half cadence, the consequent flirting with our dominant key, before ending on a PAC. The second phrase not only flirts with the dominant, but takes it out to dinner and a movie, modulating immediately before a half cadence on the fourth measure, ending on a PAC in D Major to end the phrase. This whole section is repeated in order to offer even more contrast between the sections. The second section begins with a flourish in the right hand in our original G major, before quickly a D# comes in, pulling us into our parallel minor key. We continue to a half cadence in the minor and the entire consequent phrase remains in minor, ending on a PAC. Now things get interesting, we have a cadential extension for two measures as we move to a PAC in our original key(with a similar melodic function as the first section). Finally we have a terminative section, with a vast harmonic motion and a virtuosic right hand section playing fun and happy 16th notes, before terminating 6 measures later in a final PAC in our G major key. This ENTIRE section is repeated, adding nothing new while also simultaneously distancing this section from the original material. This is a closed binary form, since it begins and ends in the same key. It is also simple since we don't really bring back the premier material except for a single cadential function.
In the immortal words of Forrest Gump: "and that's all I have to say about that."