The Rondo from the Keyboard Sonata in C K.19d for piano 4 hands is an intermediate level piano duet. It is believed that this work dates from 1765 and was possibly played by Mozart and his sister on a visit to London when more than likely it was played on a harpsichord. A rondo is a piece with a recurring theme and the form of this movement can be represented by the letters A B A C A D A E A. The realization plays back at a tempo of 110 quarter note beats to the minute. Each section is played at the same tempo apart from the Adagio E section. The appoggiaturas marked in the score can be and are interpreted differently by different performers. The music was only discovered in 1921 and whilst in the past it has been attributed to W.A Mozart the current view is that it was more probably composed by either his older sister Nannerl or his father Leopold. Suffice to say there is much of Mozart's classical musical style in this sonata whichever one of the family composed it! The sonata has some very appealing musical content and as a work, most probably written by a child, it is interesting to play and compare to W.A. Mozart's later and more substantial piano 4 hands music such as the piano Sonata for Piano 4 hands in C K.521. There are several variants in terms of the scores available but the sheet music score and realisation are based on current performance practice. 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 110 quarter note beats (crotchets) to the minute, Accompaniment 2 plays at 106 quarter note beats (crotchets) to the minute and Accompaniment 3 plays at 100 quarter note beats (crotchets) to the minute There is a 4 bar count in featuring the sound of a wood block. When performing printing two pages of music onto one side of A4 offers a very practical solution for players.