Nocturne Op. 9 No. 1: opening chords and form
B♭ minor85 bars6/4LarghettoLevel 5 of 85-page PDF
Form
A theme over a B♭ pedalA′ theme, variedB D♭ major, sotto voceC over a D♭ pedalA″ theme, last timeCoda ends in B♭ major
Bars 1–4 in B♭ minor
Sections
A (1–8): the theme
Chopin's bass holds B♭ while bars 1–4 alternate i and V⁷, and bars 5–7 reach D♭ (III) then G♭ (VI), which turns minor in bar 6.
A′ (9–18): the theme, varied
Bars 9–12 repeat the opening chords under new runs. Bar 13 reaches E♭ minor (iv) through B♭⁷, and bar 17 passes through C♭ major, the Neapolitan ♭II.
B (19–50): D♭ major
In bar 23 A⁷ lifts the harmony a half step into D major (I, IV, I), C♯°⁷ leads back to D♭'s dominant in bar 26, and the same turn comes four times.
C (51–70): over a D♭ pedal
Chopin's bass holds D♭ from bar 51 to 66, then D♭ major takes a raised fifth, A, which rises to B♭ in bar 70 and brings back B♭ minor.
Coda (80–85): B♭ major
A German sixth, C♭ E♭ G♭ A, sounds over a held B♭, and in bar 84 E♭ falls to D natural while C♭ and A close onto B♭, so the last chord is B♭ major.
Study edition
Partial analysis: opening bars and a short note on each section. The full breakdown of every section is in the study edition of Nocturne in B♭ minor.
Where it sits among the other twenty is in the nocturnes ranked by difficulty, the method for learning it from these chords is in how to memorize a Chopin nocturne, harmony first, and the left-hand pattern under it is measured in Chopin’s left-hand patterns, ranked by stretch.