Art is not putting 2 objects together. It's a conscious effort to understand and express the world around you. While Mozart's 6 year old compositions may have been entertaining, it was 20 years of musical development that allowed him to write his late piano sonatas (which may have taken him only 20 minutes to compose). That is not just craftmanship: composers who do not 'make it' often become the craftsmen by working as transposers and editors.