It was suggested to me to look into Sor’s Study No. 16, Op. 31 (Segovia edition No. 8) by my friend and colleague Tony Hyman in South Africa. What piqued his interest is the most interesting and striking harmony that occurs in measure ten, second half of beat two. How do we analyze this harmony? What exactly are the chord tones? Very interesting questions that can often times have multiple answers. Let’s look into this excellent little composition.
The form is rounded binary as is common with many of Sor’s studies. This is a two part piece in which the opening material is restated in part before the close of the second section.
So there is no confusion, I am counting both endings as measure eight.
Part One (mm. 1-8) In D minor (i) closing with a cadence on the dominant A minor (v). Notice that the dominant key area of a minor key is also minor, not major as the dominant harmony would be.
Part Two (mm. 9-24) Begins in the relative major (F major) and returns to D minor with a cadence on the dominant (A) in measure sixteen. The return of the first four bars of the opening material begins in measure seventeen and the piece then concludes with another four bars of material in the home key of D minor.
I use my two stave analysis which shows a reduction analysis of the music in the lower staff along with the usual harmonic analysis and chord labeling. The reduction staff was the most revealing for me. This clearly shows the underlying structure as well as Sor’s genius.
When the running bass line is reduced to quarter-notes, ascending and descending tonic triad arpeggios are revealed, first up to the dominant (A) in mm. 1-2 and then down to the dominant in mm. 3-4.
In mm. 5-6 again an ascending arpeggio moves to the dominant key area (A minor) before returning through the descending triad arpeggio in mm. 6-7 setting up the classic cadential ii-V-I in A minor in mm. 7-8. Sor does seem to favor ii-V-i over iv-V-i for his cadences.
Also make note of the voice-leading in the upper voices, mainly ascending and descending thirds and sixths.
The first four bars are based on a sequential idea again making use of an arpeggio in the bass and descending and ascending thirds in the upper voices (reduction staff), which brings us to our most interesting harmony in measure ten.
I would hear this chord (the second half of beat two of measure ten) as a D7 or F# diminished if you prefer moving to G minor making it a V/ii as indicated in F major. I hear the Bb as an accented passing-tone. In the big picture you can see that the bass line in measure ten into eleven is a descending scale (C-Bb-A- G) while the upper voices are ascending in thirds E/G-F#/A-G/Bb at the same time. The two clash at the second half of beat two generating a beautiful dissonance. It is interesting to note that this happens quite often in contrapuntal music. As a matter of fact almost every possible altered and exotic harmony can be found in the music of J.S. Bach if we stop the music in time and look at the vertical alignment of the voices. The line though is what rules.
Following this sequence in mm. 13-14 is a beautiful little passage of descending 7-6 suspensions leading to the half cadence on the dominant in measure 16 prepared by the neat little chromatic move in the bass (G-G#-A) in the preceding measure generating a secondary dominant (V/V).
Finally in mm. 17-24 we have the return of the opening material and the close in D minor. I really like the bass line in mm. 21-22 (reduction) before the closing cadential progression. Speaking of interesting harmony, take a look at what he does with "God Save the Queen" in Study 10, Op. 6., you won’t believe it!
One final note; When comparing an original early Sor edition with Segovia's I noticed two discrepancies:
1) Measure six shows a B-natural where Segovia has a B-flat.
2) Measures two and eighteen have a dotted rhythm in the bass that is missing in the Segovia.