Violin Sonata in B flat major K.454 (1774)

When he started on his Sonata in B flat K.454 Mozart hadn’t been able to complete a violin sonata in three years. What inspired him to finish this one, having failed with the last four attempts, was the opportunity to play it with a violinist he admired before an audience he was keen to impress. Even so, he was scarcely able to finish it on time for Regina Strinasacchi’s much anticipated concert in Vienna on 29 April 1784. The violin part was fully written out but the piano part Mozart apparently either played from memory or extemporised. There is a story that the Emperor Joseph II, who was in the audience at the Kärntnerthor Theatre, noticed that the composer seemed to be playing from a blank page and sent for him afterwards to confirm that this was indeed the case. The unusually erratic state of the manuscript seems to confirm that the violin part was written first and the piano part squeezed in later.

The Strinasacchi sonata is introduced by an appropriately impressive Largo, with double-stopped chords and a long-bowed violin melody which the piano converts to its own use by adding elaborate decorations. The first subject of the Allegro is comparatively plain in line but, set against the repeated quavers in the bass, impulsive in rhythm. The intensity is sustained throughout the exposition – not least by means of the contrapuntal treatment applied to both main themes – until, with exquisite timing, the charming closing theme transforms the atmosphere. The increase in contrapuntal activity in the recapitulation makes the contrast at the end of the movement all the more striking .

The E flat major Andante is perhaps the most intimately written slow movement in all Mozart’s violin sonatas. The blend of G and D string chords on the violin with the piano’s rising and falling octaves in the last two bars of the main theme is only the first of many colour subtleties. The next occurs when the roles are reversed a few bars later. The expressive changes of harmony in the middle section are beautifully contrived for the two instruments together and the scoring in the recapitulation is even more elaborately and effectively coloured.

There is no lack of colour inspiration in the final rondo either, although the most remarkable quality of this movement is its melodic abundance – two themes in B flat, another theme and two variations on it in the first episode, and an even better one intriguingly developed in the second episode. With such a wealth of material, and a coda brilliantly written for a final virtuoso effect, Strinasacchi must have been very happy with the sonata Mozart wrote for her – even if it was at the last minute.