CHORD ANALYSIS

Chopin’s Prelude No. 20 in C minor

As an example, let us analyze the chords in Chopin’s Prelude No. 20 in C minor. The next figure shows the results. This composition has a lot of explicit chords (thus we shall not have to search for implied ones) and it has only a few nonchord tones.

Figure: The chords in Chopin’s Prelude No. 20 in C minor

There are 48 chords in this example. Some of the notes are nonchord tones. The table that follows explains all the chords and nonchord tones that occur. The table contains four columns, which are described below: 

1. Notes that imply a chord: This column duplicates the notes from the score. These notes imply a single chord, with exception of the nonchord notes that are marked with a circle and are ignored when analyzing the chords.

2. Note names in a chord: The note names of notes from the previous column are listed, with exception of the nonchord notes. Since we are talking about note names, octaves are not important.

3. Root close position of the chord: This column shows the note names from the previous column in a form of notes arranged as a stack of thirds. Arbitrary octaves can be used. We used octaves 4 and 5. This column gives us the root close position of a chord.

4. Chord: The chord name can be read from the root close position of a chord in the previous column. The position of the chord can be read from the lowest chord tone (bass tone) in the first column.  

The table should be read row by row, from the leftmost to the rightmost column.

We can see that the following appeared:

• Major triad 

• Minor triad 

• Dominant seventh 

• Minor seventh 

• Diminished seventh 

• Half-diminished seventh 

• Dominant seventh flat five

Most of the chords were in the root position.