He resigned his position at court and began a trip with his mother in September of 1777. He traveled to Mannheim, Paris and Munich and on this trip he met many other musicians and continued to compose. The trip didn't end up with any new employment, and added to that disappointment was the death of his mother in Paris in 1778. While he was on this trip he composed seven Sonatas For Keyboard And Violin as well as other music. Six of these sonatas were published in Paris in 1778.
There was once the thought that this sonata in E minor was written after his mother had died, but there is no evidence for that. Out of 36 Sonatas For Keyboard And Violin, it is the only one written in a minor key and the only instrumental work that Mozart ever wrote in E minor. The title of all of Mozart's works in this genre is a reflection of the era in which they were written. These were essentially keyboard sonatas with violin accompaniment, but Mozart and other composers were changing the genre so that the violin was more of an equal participant. The Sonata For Piano And Violin In E Minor is in two movements:
I. Allegro - Evidence of the equal partnership between keyboard and violin begins straight away with the first theme played in unison by both instruments:
II. Tempo di minuetto - This movement also begins in E minor and makes excursions into other major keys. But it returns to the contemplative and graceful minuet melody. The middle section is music in the calming key of E major. The plaintive minuet returns and with a short coda the sonata is brought to a close.