All musicians practice ear training constantly, whether or not they are cognizant of it. If, when listening to a piece of music, a musician is envisioning how to play it or is trying to play along, that musician is using his or her 'ear' - the understanding and recognition of musical elements - for guidance.
Steve VaiI could never overstate the importance of a musician's need to develop his or her ear. Actually, I believe that developing a good 'inner ear' - the art of being able to decipher musical components solely through listening - is the most important element in becoming a good musician.
Steve VaiI designed a guitar for Ibanez and then they started manufacturing it - it's called the Jem - it's 26 years old and I still play it. As a kid I liked Les Pauls and Strats, but they had limitations for the kind of playing I wanted to do.
Steve VaiIt is only the most elite of elite musicians whose unconventional approach becomes convention.
Steve Vai