Piano Concerto in C minor, K.491

There was no greater admirer of Mozart’s Piano Concerto in C minor than Beethoven. He liked it so much that he wrote cadenzas for it, to replace those which Mozart himself had improvised when he first performed the work in 1786 but, unfortunately, did not write down. Even more flatteringly, Beethoven imitated some of its most prominent features in his own Piano Concerto in C minor. He was particularly impressed by the use Mozart makes of the sombre opening theme of the first movement. Quietly introduced by strings and bassoons in octaves, it contains within it a three-note motif, an upbeat skip into a wide upward leap, that dominates the whole construction.

The varied appearance of the three-note motif on oboe and flute in the woodwind transition to the second subject is more interesting than the new theme that follows. After the entry of the solo piano, two more lyrical themes are introduced in a comparatively serene E flat major - one by the soloist, one by woodwind - but reminders of the darker mood and the angular melodic shape of the first subject are never very far away. In the development section such normal concerto activity as the bravura runs on the piano are pinned down by the three-note-motif while its arpeggios are guided by the orchestra on an inevitable progression back to C minor. In the recapitulation, where originally major-key second-subject material reappears in the minor, there is no hint of consolation.

At this point in the work - just as in Beethoven’s C minor Piano Concerto - the composer felt the need at for a contrastingly peaceful slow movement in the major. Mozart’s is a rondo structure in E flat, which consists of a beautifully simple main theme and two melodious episodes, both of the latter enterprisingly scored for woodwind in eloquent dialogue with the soloist.

Unlike Beethoven, however, even after this sublime interlude Mozart is resigned to the situation as the first movement expressed it. Of the seven variations on the peculiarly limping march theme introduced by the violins in the opening bars, five are in C minor. The exceptions are in the middle of the movement, starting with the fourth variation introduced in A flat major by clarinets and bassoons. In the fifth, a complex study in keyboard counterpoint, the soloist steers the tonality back to C minor, which makes the bright C major entry of the woodwind in the sixth variation seem all the more cheerful. But the original theme returns in C minor and, in spite of a change of metre, Mozart confirms the unhappy ending with a chromatic protest on strings and piano and an exit line for the soloist by way of a cascade of C minor arpeggios.

At an Augarten concert in Vienna one day during a performance of Mozart’s Piano Concerto in C minor, Beethoven turned to his companion and said, “Cramer, Cramer: we shall never be able to do anything like that!” He had a very good try, however, in his own Piano Concerto in C minor, from which it is inescapably clear how much he admired Mozart’s work. The two first movements have particularly much in common, including a very similar main theme which, in both cases, is quietly introduced by the strings in octaves in the opening bars. Moreover, Beethoven followed Mozart’s example in extracting one small rhythmic motif from that theme and resting the weight of his construction on it.

Mozart’s use of his structural motif is even more resourceful than Beethoven’s, partly because the former’s three-note motif - an upbeat followed by a leap of a sixth or seventh upwards - is itself so striking and so flexible. Its varied appearance on oboe and flute accompanied by two bassoons in the transition to the second subject is more interesting than the new theme that follows, and the soloist’s apparently irrelevant first entry is actually a reminiscence of that transition theme. The soloist does, however, have a mind of his own and, when reminded of the main issue by the orchestra, he wilfully distorts the motif by stretching the upward leap. The soloist is also enterprising enough to introduce a delightful second-subject theme in the relative major, which so changes the atmosphere - in spite of intervening echoes of the main theme - that oboes and clarinets are later inspired to introduce another in the same key.

However, although the exposition ends in E flat major, and although the development begins innocently enough with the theme of the soloist’s first entry, the strings immediately and firmly recall the main theme in F minor. The piano runs are pinned down by the three-note motif and its arpeggios guided by the orchestra on an inevitable progression back to C minor. In the recapitulation, where the originally major-key second-subject melodies all reappear in the tonic minor, there is no hint of consolation.

Both Mozart and Beethoven felt the need at this point for a contrastingly peaceful slow movement in the major. Mozart’s is a rondo structure in E flat, which a beautifully simple main theme and two episodes, the latter scored for woodwind in eloquent dialogue with the soloist.

The great difference between the two composer - both at the age of thirty when they wrote their C minor Piano Concertos, incidentally - is that whereas Beethoven’s characteristically optimistic spirit wins through in the end, Mozart is resigned to the situation as the first movement expressed it. Indeed by choosing variation form for his last movement, Mozart seems deliberately to have excluded the possibility of a late change to the major such as there is in Beethoven’s concerto.

According to classical convention at least, in a set of variations the key is the same at the end as at the beginning, and it does not change much in the meantime. Of the seven variations (eight including the coda) five are in C minor. The exceptions are in the middle of the movement, starting with the fourth variation introduced in A flat major by clarinets and bassoons. In the fifth, an interesting study in keyboard counterpoint, the soloist steers the tonality back to C minor, which makes the bright C major entry of the woodwind in the sixth variation seem all the more cheerful. But when the original march theme returns in C minor and, in spite of the change of metre to 6/8 - Beethoven also changes to 6/8 for the coda and changes to C major at the same time - Mozart confirms the unhappy ending with a chromatic protest on strings and piano and an exit for the soloist by way of C minor arpeggios.