Consecutive Fifths - Mozart Fifths

Mozart Fifths

In Brahms' essay "Octaven und Quinten," he identifies many cases of apparent consecutive fifths in the works of Mozart. Most of the examples he provides involve accompaniment figuration in small note values that moves in parallel fifths with a slower moving bass. The background voice-leading of such progressions is oblique motion, with the consecutive fifths resulting from the ornamentation of the sustaining voice with a chromatic lower neighbor. Such "Mozart Fifths" occur in bar 254-255 of the Act I finale of Così fan Tutte, and in bar 80 of the Act II sextet from Don Giovanni.

Another use of the term "Mozart fifths" results from the non-standard resolution of a German augmented sixth chord in the retransition of the finale of the Jupiter Symphony (bars 222-223). Mozart (and all common-practice composers) almost always resolve German augmented sixth chords to cadential six-four chords to avoid these fifths. The Jupiter example is unique in that Mozart spells the fifth enharmonically (A-flat and d-sharp) as a result of the progression arising from a B-major harmony (presented as a dominant of e-minor). Arnold Schoenberg humorously refers to these as acceptable only because Mozart wrote them. Other theorists have tried to make the case that this resolution of the augmented sixth chord is more frequently acceptable. "The parallel fifths arising from the natural progression to the dominant are always considered acceptable, except when occurring between soprano and bass. They are most often seen between tenor and bass. The third degree is, however, frequently tied over as a suspension, or repeated as an appoggiatura, before continuing down to the second degree". However, seeing as the vast majority of German augmented sixth chords in common-practice works resolve to cadential six-four chords to avoid parallel fifths, it can be concluded that common-practice composers deemed these fifths undesirable in most situations.