1. In A-flat Major 'Aeolian Harp' - As in the first set, there are some etudes in this set that have nicknames. None of them originated with Chopin, as he didn't like to put names on his works, and he didn't like others doing it either. Robert Schumann supposedly nicknamed this etude. An aeolian harp is essentially a box that has strings stretched across the top of it between two bridges that is put into a window or outside where the breeze goes over the strings and make them sound. This etude has a simple melody played in the top notes of the right hand while an arpeggiated accompaniment is played in the right hand and left hand.
Stretches in both hands as well as musical balance is the problem, as the grace note arpeggios need to be in the background while the melody is accentuated.
2. In F Minor - This piece is in cut time, essentially 2/2, but with eighth note triplets in the right hand and quarter note triplets in the left hand, so a slight rhythmic ambiguity arises. A kind of optical illusion for the ear. The dynamics are mostly subdued, and played legato throughout.
The main technical problem with this piece is playing in the correct time with both hands.
4. In A Minor - Both hands play staccato chords with a melody line emerging here and there. An atypical piece for a composer known for his love of singing piano tone.
5. In E Minor 'Wrong Note' - Of course Chopin didn't write 'wrong' notes, but this etude is full of minor second intervals, an interval that can give the impression of incorrect notes. The left hand plays large rolled chords while the right hand plays the stumbling, wrong note theme.
The initial theme is played twice before a new theme enters in E major. This new theme is in the left hand and played in chords and octaves while the right hand plays an accompaniment in thirds that goes up and down the keyboard. This new theme is played twice and followed by the opening theme , this time in a more complex form. Chopin was a composer that seldom repeated himself verbatim in music. The ending changes things again, with wrong notes and chords. Chords are held while the inner voices of both hands play a trill. An arpeggio played triple forte leads to the ending note on G-sharp, implying the music has ended in E major.
6. In G-sharp Minor 'Thirds' - Thirds are played throughout in the right hand, with the difficulty being playing them smoothly and at a relatively soft volume. The left hand compliments the thirds and make the etude more musical while at the same time adds to the difficulty. The phrasing of the left hand groups in the beginning slur over the bar line.
7. In C-sharp Minor - Next to the piano, the cello may have been Chopin's favorite instrument. He wrote some pieces that have the melody in the bass and remind the listener of the range and character of music for the cello. This etude is one of those pieces, and is sometimes referred to as the 'cello' etude.
It begins with a solo in the bass. Soon it is joined by an accompaniment played in the right hand along with a counter melody at the top of the treble clef, essentially making this an etude in three parts. Towards the middle of the piece, the left hand displays runs as the right hand plays the accompaniment and melody. To bring out the two melody parts as the accompaniment plays in the background makes this difficult musically in itself, while the technical side of the music is no easy matter.
8. In D-flat Major 'Sixths' - As the nickname implies, this etude consists of the interval of a sixth in both hands until the very last bars. It is difficult to play scales and arpeggios in sixths of course, and that is what the music demands of the player.
9. In G-flat Major 'Butterfly' - One of the most recognizable of the etudes because of the nickname. The bouncing nature of the music can give the impression of a butterfly if the listener uses some imagination.
The difficulties of this etude are the jumps in the left hand, the bringing out of the melody in the right. hand, and bringing it all up to tempo. It is the shortest of the 24 etudes, and if played up to tempo lasts just under a minute.
10. In B Minor 'Octaves' - The piece begins with brutal triplet chromatic octaves in each hand. After the opening bars, notes are added between the octaves in both hands and add to the difficulty.
After the first few bars, notes are added between the octaves as a counter melody. This increases the difficulty tremendously as these notes are held down as the octaves are played around them. The middle section has the music shift to B major along with a slower tempo. Octaves continue in the right hand, and this section also has notes in between the octave notes. The right hand plays a two-part accompaniment, then there is a short transition back to a shortened version of the original material.
11. In A Minor 'Winter Wind' - The etude begins in a quiet mood, but it is deceptive. After the first four bars, the music takes off as the right hand plays a complex pattern that is played throughout the piece while the left hand makes great leaps from playing low bass notes to chords.
The technical demands are considerable, the interpretive demands are no less so. It takes a great deal of endurance to play this etude. The final bars are a 4 - octave run of the A minor scale. There is no etude in this set (or the first set) that is less than difficult, and the 'Winter Wind' is one of the most difficult.
12. In C Minor 'Ocean' - Chopin ends the last etude of this series in the same key as the last in the first series, C minor. Both hands play in a unique arpeggio pattern, and after the first bars Chopin throws in a melody in the top note of the right hand.
Snatches of melody interlace between the hands and are to be accented and brought out from the maelstrom of sound of the arpeggiations. The two sets of etudes have a sea of technical and interpretive difficulties that are summed up with this last one.