Did he really premiered this composition missing a page?
Imagine you're under the microscope of the musical elite in Vienna and you have to produce a whole sonata in very little time. This, for Mozart, was probably the norm. But for this one, the sonata also was to be presented with the most popular violinist at the time in a special concert for the Austrian nobility. Would you ever go on stage and perform if you had no time to transcribe your musical ideas into a piece of paper.
Apparently, Mozart did. The score was written on April 21st and in only eight days (April 29th) was brought to a public performance in the Kärntnerthor Theater where apparently Joseph II (emperor of Austria) was amused by Mozart missing page.
But why is it such a big deal to miss a page on stage? It shouldn't be! Currently the world of academic music has been training musicians to depend on the score as if it was the essential part of the music. However, the score is justa map to the the real musical ideas. Mozart was the composer of the piece and he fully knew the direction of his brand new composition. He also trusted that he was working with a fantastic violinist. Yet finally, the anecdote comes from the emperor who was probably just enjoying the music and he was impressed by something that should be natural for us musicians.
Therefore, this anecdote should be used to inspire us and remember that the score is just a way to pick up musical ideas. The score is not the music itself as the black notes on a white page really have no meaning. In the meantime, we hope you enjoyed the interpretation by Guillaume Sutre of this wonderful sonata for violin and piano K. 454 in B-flat Major.