Second phrase, measures 5 to 8

The harmonic scheme becomes more interesting in the fifth measure:

Measure 5, 2nd and 3rd beat	The V degree chord of E major is followed by a G major chord. G major is the third degree of E minor (modal interchange).
Measure 5, 4th beat	G major is used as a dominant chord.
Measure 6	C major is used as an F major chord and it is followed by a G minor chord (2nd beat) before the F major dominant chord reappears in the 3rd measure.
Measure 7, beats 1 and 2	The dominant chord of F major resolves to an A major chord, which is used as the V degree of the D minor key, followed by a vii degree chord.
Measure 7, beats 2 and 4	The vii degree of D minor (C# - E - G - Bb) is used as the vii degree of Ab major (G - Bb - Db - Fb), followed by the ii and vii degrees of Ab major.
Measure 8	The cadence moves to the key of Ab major (3rd beat). The Ab major chord transforms into an Ab minor chord, which is used as the E major iii chord (Ab = G#), followed by an E major dominant chord.

Chopin uses three modulation methods in these four measures:

Modal interchange - using a chord from the parallel minor key. G major is the III degree chord of E minor and is used as the V/V chord of F major. Modal interchange is also used to transform the Ab major chord into an Ab minor chord (G# minor), which allows it to be used as an E major chord of the third degree.

Irregular resolution or common tone - where the F major dominant chord is followed by an A major chord (both chords share the note E).

Diminished chord - The D minor vii chord (C# - E - G - Bb) is used as Ab's vii degree (G - Bb- Db - Fb). Db = C# and Fb = E.

© 2018 José Rodríguez Alvira. Published teoria.com