In this article, Joseph Swain covers other elements of modulation, going further than just the pivot chord. Swain believes that although modulation is founded on the pivot chord, it is not enough to explain one of the most important harmonic events of a piece. First he expands the idea of the pivot chord into a pivot transition or a transitional passage, and slowly goes further into detail about the melodic structure and the important harmonies. The music example he uses is the 2nd movement of Beethoven's Piano Sonata op.
Swain talks about the basics phrase structure in the beginning.
The use of the antecedent-consequent phrase in the first couple of measures leading to the dominant of the key e minor, which is then repeated up an octave resolving in an authentic cadence establishing the key of e minor. We then come to our first modulation. However, Beethoven decides to go to C major. Swain goes into a number of different reasons and ways that Beethoven has prepared us for this particular key change. As mentioned above, Beethoven harmonizes the second measure of the principal motive with a C major chord, he also uses a D sharp in the motive which can be interpreted as a diatonic neighbor note in e minor, or a chromatic neighbor note in C major.