The 12 Characteristic Pieces (12 Morceaux caractéristiques) had already been published in 1838 as Six Characteristic Pieces (Six morceaux caractéristiques), comprising Nos. 1, 4, 5, 7, 8, and 12. At the time of publication, they were likely published as Op. 8 in Paris and Op. 16 in Germany. Schumann left a favorable review for these six pieces. Soon after, the remaining six pieces were added, and the collection was published as The Twelve Months. The opus number 74 was later erroneously assigned. As the title suggests, each piece corresponds to a month of the year, and all are descriptive miniatures rich in seasonal atmosphere.

Collection 1

• No. 1: G minor – Winter Night / Une nuit d'hiver
  The biting cold outdoors is evoked by staccato notes in the bass, while the latter half sings of the warmth of an indoor fireplace through a gentle melody in a major key.

• No. 2: E minor – Carnival / Carnaval
  A carnival scene. Lively gallop is depicted with octaves accompanied by appoggiaturas and crisp staccato notes.

• No. 3: D major – Retreat / La retraite
  Soldiers gather and march upon hearing the bugle call for retreat.

Collection 2

• No. 4: A major – Passover / La Pâque
  Passover is a festival commemorating the Exodus of ancestors from Egypt. It offers a glimpse into the life of Alkan, who had Jewish ancestry and was also a strict Jew.

• No. 5: F-sharp minor – Serenade / Sérénade
  May is the season of love. The wavering hearts and sighs of young lovers are vividly portrayed through the effective use of whole-tone and chromatic scales.

• No. 6: A major – Boating / Promenade sur l'eau
  A boat swaying on calm water. The same rhythm is maintained throughout, and time flows leisurely. In such an afternoon, the latter half indulges in a somewhat sentimental mood.

Collection 3

• No. 7: A major – Summer Night / Une nuit d'été
  A cool summer night. A sense of calm, as if sitting by a window and being fanned by the night breeze, pervades the entire piece. It is a piece that captures a pleasant moment, forgetting the heat of the day.

• No. 8: E-flat major – Harvesters / Les moissonneurs
  Following a dramatic introduction, a pastoral waltz is sung. After an at times passionate middle section, a calm atmosphere returns.

• No. 9: D major – Hallali / Hallali
  Hallali refers to a hunting cry. The sound of galloping horses, the pursued prey, and the resonance of horns are splendidly expressed.

Collection 4

• No. 10: F major – Rough Weather / Gros temps
  In October, the weather breaks, and ominous dark clouds gather. It enters with a tremolo in the left hand, gradually building in intensity, and the storm escalates with tremolos in both hands. It concludes with an arpeggiated chord, like a gust of wind sweeping through.

• No. 11: C minor – The Dying One / Le mourant
  
  As the cold gradually intensifies, the poor weaken and die on the streets. A repeated descending bass figure is occasionally interspersed with a chorale. The contrast between the reality of dying and the glimpse of religious solace is moving. Chorale-like insertions are often seen in Alkan's later works; perhaps they are expressions of prayer. The final high-register chord likely leads directly into the next piece, No. 12.

• No. 12: D-flat major – The Opera / L'opéra
  While the poor perish, wealthy citizens attend the winter entertainment of the opera. This piece satirizes the grand operas of composers like Meyerbeer, who were prominent at the time, with irony and pomp.