Piano Quartet in G minor, K.478 [1785]

When Mozart’s Piano Quartet in G minor was first published no one had ever seen a score like it. But instead of presenting it as something new Hoffmeister issued it an existing series “for harpsichord or fortepiano.” No wonder that forte-pianists - not to mention harpsichordists - found it difficult to make an effect with a work that, far from being a keyboard solo with string accompaniment, was the first ever example of piano and string trio perfectly integrated in true chamber-music equality.

The opening bars, for the four instruments in octaves, seem to indicate that the Viennese piano and the string trio were approximately equal in acoustic weight. This does not mean, however, that when Mozart combines the piano with the whole string trio, as he does throughout the first movement, the string instruments do not have their own individual voices. In developing the opening four-note theme the composer performs a variety of textural balancing acts to make sure that each string part can be heard without reducing the brilliance of the piano part. Mutual obsession with that peremptory theme has such a profound influence on the emotional atmosphere that the second subject, which had originally appeared in a radiant B flat major, can only be recapitulated in G minor - which unhappy outcome is emphatically confirmed in the coda.

The emotional tendency of the two remaining movements is just the opposite. The Andante is in the coveted key of B flat major and, in spite of the early hint of G minor in the first subject, there is no hint of trauma. The final Rondo comfortably and cheerfully inhabits G major, which was scarcely even glimpsed in the opening Allegro. In the coda, where the tonality crashes dramatically into the wrong key, Mozart uses the full quasi-orchestral potential of the ensemble to force it straight back into G major, where it belongs.

The Viennese publisher of Mozart’s Piano Quartet in G minor was so disappointed by his failure to sell it that he cancelled a contract that would have supplied him with two more works of the same kind. It was partly his fault, however. No one in 1875 had seen a score like it, with piano and string trio perfectly integrated in true chamber-music equality. But, instead of presenting it as something new, Hoffmeister published it an existing series “for harpsichord or fortepiano.” No wonder the forte-pianists - not to mention the harpsichordists - found it difficult to make an effect with a work that, far from being a keyboard solo with string accompaniment, is “very cunningly scored and in performance needs the utmost precision in all four parts,” as one exceptionally perceptive critic remarked at the time.

The opening bars, for the four instruments in octaves, seem to indicate that the Viennese piano and the string trio were approximately equal in acoustic weight. This does not mean, however, that when Mozart combines the piano with the whole string trio, as he does throughout the first movement, the string instruments do not have their own individual voices. In developing the opening four-note theme, which is basically what the first subject consists of, the composer performs a variety of textural balancing acts to make sure that each string part can be heard without reducing the brilliance of the piano part. Mutual obsession with that peremptory theme has such a profound influence on the emotional atmosphere that the second subject, which had originally appeared in a radiant B flat major, can only be recapitulated in G minor - which unhappy outcome is emphatically confirmed in the coda.

The emotional tendency of the two remaining movements is just the opposite. The Andante is in the coveted key of B flat major and, in spite of the early hint of G minor in the first subject, there are no traumas. It is so relaxed, in fact, that Mozart even allows himself to threaten the integrity of the string trio by awarding an occasional solo to a specially privileged violinist.

The final Rondo comfortably and cheerfully inhabits G major, which was scarcely even glimpsed in the opening Allegro, Although there is a distinct division of responsibility between piano and strings in the melodically abundant second subject, textural integrity is restored here too. And in the coda, where the tonality crashes dramatically into the wrong key, Mozart uses the full quasi-orchestral potential of the ensemble to force it straight back into G major, where it belongs.

Mozart’s Piano Quartet in G minor was the first in a projected series of three such works for the Viennese publisher Franz Anton Hoffmeister. Friend of the composer though he was, and enterprising publisher though he later turned out to be, Hoffmeister was so disappointed by the public’s reaction to the first of the piano quartets that he cancelled the contract. The Piano Quartet in E flat major, which was completed a few months after the G minor and published by Artaria, was presumably intended in the first place as part of the same series.

The public’s reaction to the Piano Quartet in G minor was to some extent the publisher’s fault. In 1785 no one had seen a score like it – with piano and string trio perfectly integrated in true chamber-music equality – but, instead of presenting it as something new, Hoffmeister published it an existing series “for harpsichord or fortepiano.” No wonder the forte-pianists of the day – not to mention the harpsichordists – found it difficult to make an effect with a work which, far from being a keyboard solo with string accompaniment, is “very cunningly scored and in performance needs the utmost precision in all four parts,” as one exceptionally perceptive critic remarked at the time.

The opening bars, for the four instruments in octaves, seem to indicate that the Viennese piano and the string trio were approximately equal in acoustic weight. This does not mean, however, that when Mozart combines the piano with the whole string trio – as he does throughout the first movement – the string instruments do not have their own individual voices. In developing the opening four-note theme, which is basically what the first subject consists of, Mozart performs a variety of textural balancing acts to make sure that each string part can be heard without reducing the brilliance of the piano part. In the second subject piano and strings introduce one new theme each – a rhythmically ingenious one on the piano, an innocently happy one on the strings. But the division of responsibility is not sustained. Nor is the B flat major brightness that prevails at this point. Mutual obsession with the peremptory first-subject motif dominates the development and has such an profound influence on the emotional atmosphere that the second subject can only be recapitulated in G minor – which unhappy outcome is emphatically confirmed in the coda.

The emotional tendency of the two remaining movements is just the opposite. The Andante is in the coveted key of B flat major and, in spite of the early hint of G minor in the first subject, there are no traumas. The final Rondo comfortably inhabits G major, which was scarcely even glimpsed in the opening Allegro, and the strong minor-key tendency of the development scarcely shakes its security. Textural balance is maintained in much the same way as in the first movement. In the Andante Mozart is inclined to compromise the integrity of the string trio by allowing the violin a short solo here and there. In the Rondo, although there is a distinct division of responsibility between piano and strings in the melodically abundant second subject, integrity is restored. It is not, however, until the coda, where the tonality crashes dramatically into E flat major and must be forced straight back into G major, that Mozart allows himself to use the full quasi-orchestral potential of the ensemble.