thomsax said:
The theory is a way to make things more efficient?
If you're playing a bunch of memorized riffs and arpeggios then you're not really playing by ear. If you're playing melodically by ear then you're generally not using Jazz Theory and instead playing what you hear works as a melody or otherwise.
There is also a huge difference between playing using "Jazz Theory" as opposed to learning general music theory. Education can be enormously beneficial, yet when/if it's dictating a falsehood (like one can ONLY learn to improvise using theory), then its totally wrong. Playing melodically doesn't mean that you don't understand theory or haven't studied it. Likewise having knowledge of theory shouldn't = using Jazz Theory exclusively. It's not an either or, yet developing the ability to play by ear or melodically certainly isn't stressed as part of Jazz Theory.
Playing for some years gives some players the ability to hear a line and play it. It's the instrument becoming your voice. Playing by ear is less about running improv lines for technical effect and more about being creative and truly composing on the spot, whether it's jazz, pop, rock, blues...etc.
Playing by ear isn't just memory or "finger memory" where you're playing a practiced tune, using a well practiced riff, or plugging in well worn lines that simply fit the changes. Even something as simple as playing a harmony, (as long as it's not "lockstep"... all thirds, fifths etc.) can be improvisation since you've got to hear that line to play it in a spontaneous situation.
All knowledge helps, yet if one is stuck in just playing by reading or using jazz theory, and never attempts breaking free of it, then it's certainly not a stepping stone to playing by ear. All genres, styles, and modes of playing take time, energy and practice to master.
Bottom line... Education can be very beneficial, yet one must eventually direct themselves toward their goal. Creativity can be encouraged, but unfortunately not taught. If all you want is to play in a formulaic manner, then all you need are those formulas... and that's the antithesis of playing by ear.