Chopin begins his Nocturne in D Flat Major with a simple arpeggiated sixteenth note pattern in the bass voice. Figure 1.1 This pattern is non-motivic due to the nature in which it provides stability for the melody above it, but it can still be labeled as a key theme in the piece because of how Chopin transforms it throughout the work. In measures 1 through 4, the pattern is used to reinforce the presence in D flat major by arpeggiating the tonic triad. This pattern begins to evolve first in measure 5 when it outlines an A diminished 7 chord, the first chord not diatonic to the key of D flat major. From measure 5 on, the pattern travels through various tonalities. Though the pattern is transformed harmonically, Chopin never alters its’ rhythm of six sixteenth notes. It is rhythmically identical each time it occurs, which is every measure aside from the ultimate one.
[pic]
The first theme, which consists of smaller motives within itself, begins in m. 2and ends in m. 9. This theme (theme I) begins on F5 and also ends on F5. It outlines the tonic triad with likewise tonic support in the bass voice. Theme I is reiterated on multiple occasions throughout the piece and when it first appears, it is a single melodic line with only the bass voice underneath, but as the piece develops, so does the theme. Theme