Mel MartinOver at the JazzTimes, Mel Martin wrote an absolutely fascinating article regarding the internalization of music.  It is a long post (in two parts, actually) and covers a wide range of deep topics.  Each paragraph could be a chapter in a book.  

I've gone through and highlighted some of the parts that resonated with me.  Be sure to read both parts, but be prepared.  Internalizing music calls for A LOT of study and practice.