Once regarded as the high-water mark of his work in the form, the two Nocturnes of Frédéric Chopin's Opus 37 gradually fell into disservice during the course of the twentieth century. They are, nevertheless, wonderful specimens, being something of a hybrid between the more dramatic Opus 27 and the far simpler textures and moods of Opus 32. It is perhaps important that Robert Schumann considered these two works to be examples of Chopin at his finest, declaring them to be "of that nobler kind under which poetic ideality gleams more transparently (than the earlier Nocturnes)."
The first of the pair, the Nocturne in G minor, Op. 37/1, is cast in the characteristic three-part (ternary) form. The opening and closing sections are of great sadness; the initially restrained primary theme quickly gains in passion upon its repetition some 16 bars into the piece, and only the sudden intrusion of a subito piano dynamic during the second phrase of the repetition curtails the torment. Consolation is found in the chorale-like chords of the central section of the piece; the texture is absolutely plain: not a single eighth note interrupts the procession of steady, quarter note chords, and no dynamic above piano is allowed by the composer. Some biographers have felt that this music represented Chopin's faith in the consoling power of religion. The reprise of the opening section is literal (if truncated to some degree).
The Nocturne in G major, Op. 34/2, is of an altogether different breed, with its barcarolle-like meter and sweet melody in parallel voices. It is quite possible that this particular Nocturne was composed during or shortly after Chopin's 1838 stay with writer George Sand on the Island of Majorca, and that something of the warmer Mediterranean climate crept into the composer's pen. The second theme of the Nocturne, a simple tune that varies very little from its initial pattern, has been judged by many to be the most beautiful melody Chopin ever composed (Chopin recorded that he himself felt the melody of the E major etude from Opus 10 to be his finest such achievement); at any rate, the theme is certainly a musical embodiment of the "less is more" doctrine. This second theme returns after a truncated reprise of the opening, more active material, and it wins out once again at the end of the piece.