Piano Sonata in C minor, K.457

Mozart’s Piano Sonata in C minor was the first work of that kind that had completed in six years. He had not abandoned the keyboard - there are the three Concertos K.413-5 as ample evidence to the contrary - but when he returned to the piano sonata it was as though he had rediscovered not only the form but also the instrument. Perhaps the truth is that it was not until now, after the experience of the piano concertos, that he had learned how to exploit the new possibilities of the Stein pianoforte (or fortepiano) which he had first played and so much admired in Augsburg in 1777. Certainly, Mozart devoted so much of his imagination, skill and expressive power to this sonata that it had a profound effect on Beethoven, whose early sonatas, particularly those in C minor, reverberate with its influence. The short development section of the first movement, beginning in C major and plunging dramatically into F minor, is an inspiration which Beethoven faithfully imitated in his Op.10 No.1.

As for Mozart’s skill in exploiting the Viennese pianoforte, the slow movement offers numerous examples. Structurally, this Adagio resembles nothing more adventurous than a set of variations. But between the several reappearances of the opening melody there are interludes of considerable harmonic and colour interest - like the repeated quiet staccato on top F, at that time the very top note of the keyboard, the note-by-note alternation of forte and piano crossing the rhythmic accents, the little cadenzas, the legato broken chords… The very lowest note of the piano as Mozart knew it is featured in the Molto allegro - an extraordinarily bold rondo of abrupt modulations and changes of temperament, punctuated by pauses and silences and oddly coloured by the right hand’s fascination for the extreme low notes of the keyboard.

When Mozart wrote his Piano Sonata in C minor, in Vienna in 1784, it was the first work of that kind that had completed in six years. He had not abandoned the keyboard - there are the three Concertos K.413-5 as ample evidence to the contrary - but when he returned to the piano sonata it was as though he had rediscovered not only the form but also the instrument. Perhaps the truth is that it was not until now, after the experience of the piano concertos, that he had learned how to exploit the new possibilities of the Stein pianoforte (or fortepiano) which he had first played and so much admired in Augsburg in 1777.

Certainly, Mozart devoted so much of his imagination, skill and expressive power to this sonata that it had a profound effect on Beethoven when he encountered it. There is no documentary evidence to prove this, nothing to parallel the account of Beethoven listening to Mozart’s C minor Piano Concerto in 1799. But, just as the Concerto had an immediate effect in Beethoven’s own Piano Concerto in the same key, so Mozart’s C minor Piano Sonata echoes throughout Beethoven’s early sonatas, particularly the two in C minor Op.10 No.1 and the Pathétique Op.13.

The triadic outline of the first subject of Mozart’s opening Allegro is common enough, but partly because it is a C minor image stamped by Mozart on classical music. The second subject is a conventional enough contrast in the relative major. But the short development - beginning in C major and plunging dramatically in F minor - is an inspiration which Beethoven faithfully imitated in his Op.10 No.1.

As for Mozart’s skill in exploiting the Viennese pianoforte, the slow movement offers numerous examples. Structurally, this Adagio resembles nothing more adventurous than a set of variations. But between the several reappearances of the opening melody (with differing decorative surfaces but always in E flat major) there are interludes of considerable harmonic and colour interest - the repeated quiet staccato on top F (at that time the very top note of the keyboard), the note-by-note alternation of forte and piano crossing the rhythmic accents, the little cadenzas, the legato broken chords, the quiet repeated staccato at the other end of the keyboard.

The very lowest note of the piano as Mozart knew it is featured in the Molto allegro. This is an extraordinarily bold rondo of abrupt modulations and changes of temperament, punctuated by pauses and silences and oddly coloured by the right hand’s fascination for the extreme low notes of the keyboard.