Types of Augmented 6th Chords used by Mozart

Mozart used the Italian, German and French forms of the augmented 6th chord. The latter two

are supersets of the Italian form, containing an extra note in each case. That is:

          Augmented 6th   -   2 notes                                                (such as  D#--------C#)

          Italian 6th           -   3 notes  =  augmented 6th + 1 note      (such as  D#-G-----C#)

          German 6th        -   4 notes  =  Italian 6th + 1 note             (such as  D#-G-A#-C#)

          French 6th          -   4 notes  =  Italian 6th + 1 note             (such as  D#-G-A--C#)

Even when Mozart used the German and French forms of the augmented 6th chord, he was still using

the notes of the Italian 6th to form the basic structure of the chord.

The origin of the names "Italian, French, and German" 6th are unknown.

Reason for its Use

It is not known if Mozart intentionally used this phrase as a way of musically "signing his name",

as an artist would sign his name, or if he simply used it because he liked the phrase,

and its use seemed fitting for a particular location in a piece. Unless a letter or other evidence

turns up where he mentions its intentional inclusion, we may never know his motivation for

using it so often.

Mozart used the phrase so often and in so many different ways, that it is safe to say that

he had an endless fascination with it. Perhaps that was his reason for using it.

Since the phrase does not appear in all his pieces, it might seem that it is not a musical

signature or musical trademark, and would be the equivalent of van Gogh signing some of his

paintings, but not all of them. However, not every piece permits its use, musically

speaking: Some are too short, some have the wrong "ambience", etc. While van Gogh could

sign his name to every painting, Mozart could not do the same to every composition.

In general, the trademark phrase appears in pieces, which are long enough to permit it, and have

the right musical ambience - sometimes appearing multiple times in a single piece and even on a

single page.

Meaning of its Use

Since we don't know the reason Mozart used this phrase so often, it's difficult or impossible to

assign a meaning to it. However, some elementary conclusions can be drawn:

1. The phrase illustrates the kind of music Mozart liked - at least, in terms of 2 chords.

2. The phrase illustrates the kind of music Mozart was fascinated by.

3. We can see Mozart's creative abilities at work on a single phrase as he invents different forms

    of the phrase.

4. The phrase represents Mozart's music to a degree, since it is so pervasive and often throughly

    embedded..

We can also speculate as to whether the phrase may have represented Mozart himself, at times,

 being used as it was in the highly personal piano rondo K.511, the concert aria K.505, and others.

 K.505 was written as a "duet" for voice and piano for his friend Nancy Storace, with Nancy singing,

 and Wolfgang playing the accompanying piano part. There's no way of knowing if Mozart used

 the phrase in K.505 to represent himself, but since the phrase represents his music (to a degree),

 and since his music represents who he was (to a degree), it would not be much of a reach to say

 that the phrase which represented his music and who he was therefore represented him in that piece.

 If that specultation is true, then the trademark phrase is much more than a trademark: It is the musical

 representation of Mozart himself, as penned by the master.

While the phrase may not be musically significant, in most cases, allowing for little musical analysis,

 the symbolic value of the phrase may be its most important feature: It may musically represent

 Mozart in one "sound bite".

Earliest Use

The earliest use of the phrase, so far, appears to be K.19d (May, 1765, age 8) for 2-manual harpsichord,

4 hands, written for performing by himself and Nannerl, his sister.

The date is uncertain since the style of the piece doesn't appear to match Mozart's then-current style.

Wolfgang Plath has doubts as to the authenticity of the piece, but all the known facts about it seem to

make it probable that Mozart was the composer. For example, a Mozart family portrait depicts

Nannerl playing the piano in exactly the same way that she would have played K.19d as the primo

performer of the 4-handed piece on a single keyboard, with her left hand reaching under Mozart's right hand.

As an example of another early piece, it can easily be heard in the Symphony Number 6 in F Major

(K.43), written in 1767 when Mozart was 11.

Usage by Other Composers

Although used mainly by Mozart, it may also have been used frequently by Beethoven in his

early years when he was writing in the style of Mozart. 

It could conceivably be found in Handel’s Messiah and some other pieces by Handel orchestrated by

Mozart, where Mozart added his own harmony to many sections.

A candidate for occasional usage would be the music of JS Bach, and one such example is listed here

from the Mass in B Minor.

An example of the phrase from a Chopin Piano Concerto is also provided, although Chopin appeared

to be using that phrase as a rather weak bridge to some other musical idea.

The phrase can also be found in the music of Mozart's composition pupils.

It can be found in some music by (or believed to be by) Quirino Gasparini, some of which Mozart included

in one of his pieces (K.195/186d - Litaniae Lauretanae, number 3: Salus Inforum). That is, the Salus Inforum,

which contains the trademark phrase, is believed to be by Gasparini, and Mozart included that piece in his K.195 -

Litaniae Lauretanae.  Gasparini also wrote a beautiful piece called Adoramus Te which was originally

attributed to Mozart (K.327) since Mozart had made a copy of it. This piece by Gasparini also contains the

trademark phrase. So, in Gasparini's case, Mozart used or copied the pieces containing the trademark

phrase penned by Gasparini on 2 occasions, and incorporated them into his own works or study materials. 

In any event, the use of this phrase is typical of Mozart, and is part of his style in many pieces.

Except for occasional usage by other composers, its origin, usage and development centers around

Mozart.

General Characterization

The phrase consists of 2 chords. Each chord contains 3 notes.

In musical notation it is:      

(Actually Eb-G-Db for the first chord)

The 2 lower notes in each chord are major 3rds, highlighted in purple, below.

The top and bottom notes in the 2^nd chord are always an octave apart.

The 2-chord phrase always looks like this (pictorially), regardless of the actual notes used:

           Eb---G---Db          1st chord (Italian 6th)

         D---F#-------D        2nd chord (modified major triad)

      The 2 notes forming the +6 interval resolve outwardly by half steps to an octave.
      Neither one of the notes forming the +6 interval moves a full step to form an ocatve.

       The note comprising the major third also moves by a half step.

      Additionally, the leading voice moves by a half step (Db to D in the example above).

The root key in the preceding examples is G minor.

The top note of the 2nd chord (D nat in the examples) forms the dominant note for the root key.

Thus, we usually see the progression: 

               
   G---Bb---D---G  ==>  Eb---G---Db  ==>  D---F#---D  ==>  G---Bb---D---G
         Minor            (Minor)            Major            Minor  

      i of G minor         It#6          V of G minor     i of G minor     

                      Typical progression from minor, to major, and back to minor.

                                           The yellow portion represents the trademark phrase. 
 

The trademark phrase temporarily converts the key from minor to major, and usually continues to the

root key (which is usually minor). Thus, it is usually found where the piece is in a minor key.

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Definition of the Trademark Phrase

The definition of the phrase involves the relationships between the minimum number of notes which

describe the phrase, as well as other factors.

Definition 1 (musical):

1. The phrase being defined is referred to as "Mozart's MTM" (Mozart's Musical TradeMark) or simply,

"the MTM".

2. The MTM phrase consists of 2 chords, with each chord containing 3 notes.

3. The first chord consists of a major 3^rd for the lower 2 notes, and an upper note a +6^th higher than

the lower note.                                                                      

4. If any additional notes accompany the first chord in the original music, and they are lower than the

lowest note of the first MTM chord, then the lowest accompanying note must be the same note as the

lowest note in the chord, lowered by 1 or more octaves.            

5. The second chord consists of a major 3^rd for the lower 2 notes and an upper note an octave above the

lower note.

6. The lowest note in the 2^nd chord is 1 semi-tone lower than the lowest note in the first chord.  

7. The 2 notes forming the +6 interval in the first chord resolve outwardly by half steps to an octave in the

2nd chord.                                                                                

8. The note comprising the major third in the first chord (the middle note) moves down by a half step in the

2nd chord.                                                                            

9. The 2nd chord (the resolution) must appear within 2 measures of the first chord.

10. Key signature is not a factor in the definition.

11. Musical nomenclature involving chord names or types are not part of the definition.

12. For MTM determination, some notes in the original music may need to be eliminated  to strip away

unnecessary notes, based on the rules below. See "Reduction of Notes" below.

13. For MTM determination, some notes in the original music may need to be be interpolated based on the

 rule "Interpolation of Notes" below.

14. If the 2 chords match the criteria described above,  then the phrase is a “musical trademark” phrase,

or "MTM", whether by Mozart or another composer.                              

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      Note: Rather than using the formal definition when searching for the phrase, it may be easier to
      use  the earlier examples for comparison, and mentally convert the notes on the sheet music to
      their equivalent locations in the examples, or to quickly check the chord relationships using the
      examples  as references.

Additional Attributes and Rules

Nomenclature

The first chord of the phrase is an "Italian 6th"- not a "dominant 7th" - even though the notes in the

two types of chords may be identical.

The standard chord names are used as a shorthand  in describing the notes, but the definition

of the phrase, above, is what determines a phrase's qualification to be called a "trademark phrase."

MTM Determination:  Reduction of Notes

Compression

Compression is simply a preliminary note-removal process, stripping away some of the non-essential

notes to illuminate the trademark phrase.

Where the notes in the 1st or 2nd chords are separated by more than 1 octave from each other,

pitches may be raised or lowered by octave intervals (compressed) as long as their relative positions

in terms of "higher" or "lower" remain the same. This applies to all notes in both chords.

Additionally, intervening notes, if any, are deleted.

Example of compression:

      As Written:       Eb-Eb---G-Bb-C#-Bb-C#    ===>    D-D----F#-A--D-F#-D

      Compressed:          Eb---G----C#-Bb       ===>      D----F#----D-F#