The second sonata, in E-flat major, in the set is one of the hidden jewels, due to the fact that it is not often performed. It has two movements, like most of the set and the violin has a more prominent role than before and one can see clearly a very different style than the Sonata in G major, Kv.301.
The first movement is one of those typical movements starting with a 'Forte' opening of a broken chord. It is typical because he does this type of openings in more Sonatas, for example, Kv.305 in A major and Kv.296 in C major, though every time breaking the chord in a different way. Always after these type of opening, Mozart uses a very melodic part to counter this opening that can be seen as a 'shocking' from the fact that it opens loud and very rhythmical. This movement is a very uplifting piece of music and the main emphasis is on the metre and preciseness in rhythm. Especially in the more rhythmical parts, it is based upon repetitive notes or figures, something that is also one of the main elements in the second movement.
The second movement is one of the most beautiful melodies in the set of 301-306. Again in E flat major but with a more complex harmonic pattern we face a genius movement that balances greatly the first movement which was more direct and concrete in metre. This movement hints towards the style of a concerto with soloist elements which is being accompanied by the other instrument, sometimes the violin and other times the piano. Often the violin repeats in a slightly varied way what the piano introduced. This can be seen in the three sections in the beginning. In the middle part, we can see that Mozart puts the violin an octave lower, with exactly the same line, from the piano. With more than 30 bars of playing the melody together, we return back to the main theme which results in a bridge towards a Fermata, that was usually played out like a short improvised cadenza. After this part, we come back to the doubled melody part and with again a short bridge we come back to the first theme but now played only by the violin and being accompanied with just triplets and a bass line for the piano. This section should be played extremely soft to make the repetition, in which the piano joins the violin (now playing an octave higher) with the theme, as grand as possible, also the accompaniment in the left hand of the piano, with broken octaves and broken chords, which is played in the lowest register on the piano at those time, make this climax have a feeling of grandeur. The simple coda at the end, with the thematic material of the first theme and a very simple accompaniment of the violin concludes this sonata.