Nocturnes, Op. 55 (Chopin)

The two Nocturnes, Op. 55 are a set of two nocturnes for solo piano written by Frédéric Chopin. They are his fifteenth and sixteenth installations in the genre, and were composed between 1842 and 1844, and published in August 1844.
Nocturne in F minor, Op. 55, No. 1.
Composed in 1842-1844, the F minor nocturne has an average duration of about 5 minutes.
Structure.
The piece is in ternary form (ABA). Its main theme has a slow 4/4 with a heavy, steady crotchet beat. It starts with the main theme which repeats once with only minor variations. The right hand plays a slow melody and the left hand accompanies with a bass note and then a chord, in crotchets. The second section is then played with, again, the right-hand playing the melody and the left-hand accompanying with bass notes and a chord. Although there are occasional changes to this pattern, for example the left-hand plays a sustained minim with a crotchet chord above. The main theme then comes back in with some variations to the first two times it was played: a triplet phrase is added to the 3rd bar of the section. The second section is again repeated with no variations, followed immediately by the first section again with the triplet sequence.
A tempo change to "più mosso" speeds up the piece. It starts off with some fast, triplet quavers and then three loud (forte) chords. This then repeats three further times until a completely new section comes in with a melody in the right hand and triplet broken chords in the left (see score on right). A descending scale and some large chords completes this section and leads it onto the first theme again.
There is then a large variation on the first theme where the main tune is played with other notes in between. There is then a large section of arpeggios and finishing off on 6 final chords. Modulating to the parallel key of F major for an interrupted final cadence.
There are two short chorales. The first, at bars 71-72 marks the transition from B section back to A, while the second, at 98-101, concludes the piece, in F major.
The piece was described by Frederick Niecks (Chopin's biographer) as: "we will note only the flebile (feeble) dolcezza of the first and the last section, and the inferiority of the more impassioned middle section".
Notable performances.
This piece was performed by Vladimir Horowitz in his television debut concert at Carnegie Hall in 1968, which was broadcast nationwide by CBS.
Nocturne in E-flat major, Op. 55, No. 2.
The second nocturne in E major features a 12/8 time signature, triplet quavers in the bass, and a "lento sostenuto" tempo marking. The left-hand features sweeping legato arpeggios from the bass to the tenor, while the right-hand often plays a contrapuntal duet and a soaring single melody. There is a considerable amount of ornamentation in the right hand, for instance the prolonged trills in measures 34 and 52-54. The characteristic chromatic ornaments, in measures 7, 25, 36, and 50, often subdivide the beats in a syncopated fashion in contrast with the steady triplets in the left hand.
Of this nocturne, Niecks wrote:
In theatre.
The second and third duets of the ballet "In the Night" by Jerome Robbins (1970) were choreographed to this music.