This is no discovery....
want to improve your playing? Regardless of your level of technique
listen to the drummer or bassist rather than the guitarist. Get your
groove on and people will respond to you better. The best players
are rhythmic players.
What to play like Stevie Wonder? Learn to sing his style of music
and then play your vocals.
Practice humming a note and then going to your harp and play that
same note without finding your bearings on the instrument. KNOW where
every sound and note is on EVERY harmonica. This is the beginning to
being able to play what is in your head.