The Molto presto third movement of the Sonata for piano duet in B flat K.358 is a positive, joyous and like much of the composer’s music uplifting. The realisation plays back at a tempo of 108 half note (minim) beats to the minute. The first repeat is played in the realisation whilst the second repeat indicated in the sheet music score is not played. Multi-rests have not been used in the sheet music score but there are numbers in place indicating the empty bars in the sheet music score. This is a movement that does need to be played quickly and some of the tempi available on recordings are actually very challenging to play. The best advice is to start at a manageable tempo and then gradually increase it. The tempo of the movement as it is being played does however always need to be consistent. The music editor suggests setting a metronome to a half note (minim) beat minim beat in practice routines. There is opportunity for developing the “changing finger on a repeating note” technique and the playing of trills played by two hands requires careful practice. In the early stages of learning the movement the music editor suggests omitting the trills. For those wanting to see how the trills are played they can refer to the video score on our YouTube channel by clicking the appropriate link on the homepage of the website. The movement has many melodic shapes, textures and compositional processes characteristic of the composer and the music editor suggests that much can be learnt about the composer’s musical style by playing and listening to the piano duets. Mozart’s music always has a great sense of ensemble and his musical language is always consistent across the many musical forms that he embraced. The accompaniment downloads available enable players to enjoy an ensemble music experience playing either the primo or secondo parts. The Primo part sounds on the one channel of the stereo signal and the Secondo part sounds on the other. Accompaniment 1 plays at 108 quarter note beats (crotchet) to the minute, Accompaniment 2 at 104 quarter note beats (crotchet) to the minute and Accompaniment 3 at 104 quarter note beats (crotchet) to the minute There is a four bar count in featuring two different sounds of a wood block. When performing printing two pages of music onto one side of A4 offers a very practical solution for players.