Also known as the “Moonlight” Sonata, this widely known work was written in 1801. It has three movements: an unusually slow, freely treated sonata form in the first movement, and a fast sonata form in the third.
The first movement is Adagio sostenuto, 2/2, in C♯ minor. Although it adopts sonata form, the development is more compact than the exposition and recapitulation.
Exposition
First Theme
The movement unfolds by sustaining triplet arpeggios while laying a melody above. After a four-bar introduction, the first theme begins in earnest. Those four bars present the movement’s overall concept: the left hand descends by seconds to reach V. This stepwise descent recurs throughout the movement and helps bind the movements of the sonata together.
From m. 5 a soprano melody is added; the middle voice triplets continue to propel the whole piece. The soprano appears in a dotted rhythm, creating offset accents; three voices keep moving continuously. After an E-major V–I in m. 9, the music modulates to e minor and restates the subject.
At m. 12 there is a modulation to b minor. With each phrase a modulation occurs; the music does not linger long in any one key. Often the starting and ending keys of a phrase differ, showing considerable tonal change from phrase to phrase.
Second Theme
After the move to b minor in m. 12, the line immediately shifts with D♯ to B major; from here we may regard the second theme as beginning. There is no distinct transition between first and second themes; they flow naturally without sharp boundaries. Unlike the customary minor-key sonata practice, which would begin the second theme in the relative major (E major), this movement begins it in B major.
In the second theme the left hand appears in quarter notes and shows more motion than in the first theme, while the right hand proceeds more slowly in half-note units. At mm. 22–23 a cadence in f♯ minor appears and leads directly into the development. In this work, sections do not separate sharply; they slip into the next. Cadential tags and a clear codetta are not prominently articulated.
Development
The development begins by working with the first theme, starting on I of F♯ minor. At m. 28 V of C♯ minor appears and is prolonged, forming a retransition that leads to the recapitulation. As before, boundaries are not emphatically marked; the music flows naturally.
Up to the start of the recapitulation at m. 42, a G♯ pedal is sustained. The triplet arpeggio figure is expanded and intensified. After repeating two-bar phrases, from m. 34 the phrases are lengthened into four bars that ascend and then descend. From m. 38 the phrases shrink to one bar, repeating and driving toward cadence. Harmonically, diminished-seventh chords recur. From m. 40 the bass centers on G♯, with slight neighbor motions to A and F♯. Relative to the total length of the development, the retransition is strikingly long; with the cadence at m. 42 the music enters the recapitulation.
Recapitulation
First Theme
With no major change, the first theme returns in the home key C♯ minor.
Second Theme
The music continues into the second theme. Unlike the exposition, the second theme now starts in the tonic C♯ minor and remains within C♯ minor. In mm. 55–58, accidentals are used to avoid monotony while staying within the same key. A chain of secondary-dominant sevenths and their resolutions shapes the latter part of the second theme. At m. 60 a full PAC in C♯ minor arrives, and the movement passes to the coda.
Coda
The coda stays faithful to motives heard thus far. The character of the first theme is prominent: the dotted rhythm that had appeared in the soprano of the first theme is now used persistently in the left-hand tenor. The triplet flow continues unbroken. V–I motions repeat; the right-hand figuration gradually sinks into the left-hand register, and the piece fades away in pianissimo. An attacca leads directly into the second movement.
Also known as the “Moonlight” Sonata, this widely known work was written in 1801. It has three movements: an unusually slow, freely treated sonata form in the first movement, and a fast sonata form in the third.
The first movement is Adagio sostenuto, 2/2, in C♯ minor. Although it adopts sonata form, the development is more compact than the exposition and recapitulation.
Exposition
First Theme
The movement unfolds by sustaining triplet arpeggios while laying a melody above. After a four-bar introduction, the first theme begins in earnest. Those four bars present the movement’s overall concept: the left hand descends by seconds to reach V. This stepwise descent recurs throughout the movement and helps bind the movements of the sonata together.
From m. 5 a soprano melody is added; the middle voice triplets continue to propel the whole piece. The soprano appears in a dotted rhythm, creating offset accents; three voices keep moving continuously. After an E-major V–I in m. 9, the music modulates to e minor and restates the subject.
At m. 12 there is a modulation to b minor. With each phrase a modulation occurs; the music does not linger long in any one key. Often the starting and ending keys of a phrase differ, showing considerable tonal change from phrase to phrase.
Second Theme
After the move to b minor in m. 12, the line immediately shifts with D♯ to B major; from here we may regard the second theme as beginning. There is no distinct transition between first and second themes; they flow naturally without sharp boundaries. Unlike the customary minor-key sonata practice, which would begin the second theme in the relative major (E major), this movement begins it in B major.
In the second theme the left hand appears in quarter notes and shows more motion than in the first theme, while the right hand proceeds more slowly in half-note units. At mm. 22–23 a cadence in f♯ minor appears and leads directly into the development. In this work, sections do not separate sharply; they slip into the next. Cadential tags and a clear codetta are not prominently articulated.
Development
The development begins by working with the first theme, starting on I of F♯ minor. At m. 28 V of C♯ minor appears and is prolonged, forming a retransition that leads to the recapitulation. As before, boundaries are not emphatically marked; the music flows naturally.
Up to the start of the recapitulation at m. 42, a G♯ pedal is sustained. The triplet arpeggio figure is expanded and intensified. After repeating two-bar phrases, from m. 34 the phrases are lengthened into four bars that ascend and then descend. From m. 38 the phrases shrink to one bar, repeating and driving toward cadence. Harmonically, diminished-seventh chords recur. From m. 40 the bass centers on G♯, with slight neighbor motions to A and F♯. Relative to the total length of the development, the retransition is strikingly long; with the cadence at m. 42 the music enters the recapitulation.
Recapitulation
First Theme
With no major change, the first theme returns in the home key C♯ minor.
Second Theme
The music continues into the second theme. Unlike the exposition, the second theme now starts in the tonic C♯ minor and remains within C♯ minor. In mm. 55–58, accidentals are used to avoid monotony while staying within the same key. A chain of secondary-dominant sevenths and their resolutions shapes the latter part of the second theme. At m. 60 a full PAC in C♯ minor arrives, and the movement passes to the coda.
Coda
The coda stays faithful to motives heard thus far. The character of the first theme is prominent: the dotted rhythm that had appeared in the soprano of the first theme is now used persistently in the left-hand tenor. The triplet flow continues unbroken. V–I motions repeat; the right-hand figuration gradually sinks into the left-hand register, and the piece fades away in pianissimo. An attacca leads directly into the second movement.