Wolfgang Amadeus Mozart's first four sonatas for piano and violin, K. 6-9 are among his earliest works. These were composed by a budding Mozart between 1762 and 1764. They encompass several of Mozart's firsts as a composer: for example, his first works incorporating the violin, his first works with more than a single instrument, his first works in more than one movement and his first works in sonata form. In fact, previous to this, all his works had been short solo-pieces for the harpsichord. Mozart would have been between 6 and 8 years of age when he composed these works; hence it is believed by many that it was written down for the boy by his father, Leopold: all four of these early sonatas are preserved in Leopold's handwriting. All of Mozart's early violin sonatas are really piano sonatas with violin accompaniment, a fact which is made clear from the original title of the four sonatas