the structural phenomena in schubert's musical moment no. 6 include just about every element mentioned in the book, but has some exceptionally noticeable cadences and key changes. this piece begins in Ab major, but immediately tonicizes the dominant in the sixth measure. in fact, there are several V(7)/V chords throughout the allegretto section of the piece. the key changes many times, from Ab major to E major and back again and the bVI chord (in Ab) can serve as a pivot chord for a enharmonic modulation. at the trio, the key changes yet again to Db major. the d.c. at the end of the trio section returns to the opening motive, reassuring the listener that this prominitent melody has not gone astray.
as far as other elements of structural phenomena are concerned: the tempo stays relatively constant throughout the piece, leaving room for rubato here and there; each motivic gesture begins quietly, but gradually loudens, and then tapers off at the end of each phrase; AND the texture remains constant as well, because both the left and right hands move together, with the exception of ornamentation and/or lingered suspensions prolonged by either hand.