What was Mozarts earliest composition?

Answer 1

They just found a composition just a few weeks ago that they thought was Mozart's from when he was 4. The manuscript was written, they think, in his father's hand and the style was Wolfgang's. Here is an article from CNN: http://www.cnn.com/2009/WORLD/Europe/08/02/new.mozart/index.html?iref=newssearch

Answer 2

what are the most important pieces written by mozart? what are the most important pieces written by mozart?

Answer 3

He was a composer in the Classical Period.