The fourth sonata in the Mannheim violin-sonatas is always regarded as a special one. From the 36 sonatas that Mozart wrote for this violin-piano repertoire, this is the only one which is written in the minor key. It was written during the time that his mother died, in Paris. Again this Sonata has two movements, it is suggested that Mozart kept the rules of Johann Christian Bach who made it his rule to write in this form, though none of his sonatas for solo piano which were written in the same time, have two movements.
The first movement of this Sonata starts with both hands and the violin playing the same melodic line. A very rhythmical element is played afterwards to complement the melodic part of the theme. The piano closes the first section with a different theme. With this conclusion, we start with the second theme. This theme is built upon repeating notes and dotted rhythmical patterns. These are elements that bring Drama into the music. Especially the way one interprets these repeating notes is one of the key elements of the movement. What is also important to note is that Mozart wrote many things together for both instruments. And the use of counterpoint, for example before the repetition, one can note that the music becomes denser than before, making each line as important as the other.
The second movement is, like the Kv.302, in a 'Tempo di Menuetto' without the Trio section. This movement is written, again in E minor but has a very different affect. It is more optimistic and has a whole section in the E major key that is one of the most beautiful parts in the repertoire of violin-piano repertoire, ever written. Mozart wrote again in a denser way than before which can be seen at the entrances of the melodic line. Normally Mozart would finish the phrase and start the repetition or another phrase after the other phrase was done. In this sonata the counterpoint and canonic way of treating the melodies is implied, making it more playful than ever for the performers. The structure of the accompaniment is also written in a more counterpoint style, with voices going against each other, rather than a 'simple' broken chord. The conclusion of the sonata ends with a big statement in e minor and the rhythmical pattern is clearly not traditional with keeping the Menuet dance, with the 3rd beat emphasis.