John Coltrane
He probably started Blue Train by tapping and improvising... His is initially easier to do than composing first before sitting down on the piano bench
.. Then again, j may be wrong: Coltrane may very well have thought through and philosophized about it ... Then sat down with a pencil... AND THEN improvised... I highly doubt it though... Although there is definitely a rhyme and reason to his music, which many believe is some random concoction of gibberish and mumbo jumbo which eventually "sounded nice" (which this I also doubt.. As he was and may have been a music geniu as well)