Mozart, Piano Quartet in G minor

The piece I chose for this assignment is the third movement from Mozart's Piano Quartet in G Minor. Now, while the entire quartet (and name of piece) is in minor, this particular movement is actually in G major. The parts of the movement I will be examining are the opening two phrases, which together create the opening period.

Above is my phrase diagram of the opening period. I identified the meter as 2/4, however I was hesitant as whether to call it 2/4 or 4/4. In a 2/4 metering, each phrase has 8 measures. Both phrases are melodically identical, barring their endings, or cadences. Thus I labeled phrase 1 as "a" and phrase 2 as "a'" (or "a prime"). It was a bit tricky finding the cadence note for the first phrase, as the everything does not end nicely on one note. Rather, there is a quick note from the piano accompaniment. After first identifying and humming the melody's tonic ("do"), I then hummed the cadence note for the first phrase. I found that it was "sol" (the 5th), therefore meaning phrase 1 ends on an IAC. Like I said before, the second phrase follows essentially the exact same melody, however, this time brings it back home (to tonic) and ends with a perfect authentic cadence (PAC). These two opening phrases compose what is known as a "Parallel Sectional Period". 

I thought it was interesting how even though the two phrases of the period are identical melodically, they somehow sound very different. This is because of the vast difference in texture. While "a" is only one piano playing the melody, "a prime" consists of that same piano playing along with what seems like a full string quartet. The youtube video I've posted is actually very interesting as it shows a visualization of each instrument, similar to the graphs we *attempted* to draw in class.

While analyzing this period, I realized that it truly does capture the essence of the enlightenment. We talked in class about how music from the age of reason was generally very symmetrical. This period exemplifies that as does the rest of the piece, through the repetition of phrases. Another main aspect of the enlightenment that is shown through this piece is the idea of rationalizing a problem, and then coming to an agreement or conclusion. This period does that exact thing. In the first period, it is a lone piano, trying to come to a conclusion by itself. It does not really succeed, ending in an IAC, leaving the listener with an incomplete feeling. However, the piano then gets some help from the string quartet. This symbolizes, if you will, the idea of working together as a group (as opposed to just one person) to find an answer. This "answer" is shown musically with the PAC, as now the listener is left with a sense of completion.