Once again, I must reiterate that actually teaching someone how to improvise is nearly an impossible task. Yet, there is something that I consider to be “the knowledge” when it comes to music, and if you have this “knowledge”, you’ll certainly be on your way to becoming a great improviser.
The knowledge I speak of is having the true ability to not only hear the note relationships, but to also acquire the understanding of hearing these relationships and intervals in advance. This is the thing you’ll need to be able to “think on your feet”, and to be able to hear entire passages in your head even milliseconds before actually playing them. That “thought process” that goes on when you are improvising is truly critical, and when you do have an understanding of the sound relationships of the notes, their emotional impact can even more be taken into account, and to heart.
And it is a matter of the heart, as this is what people are really hearing coming from you when you play. The act of improvisation is the ability to really “speak” with your instrument, and the learning process is like life itself, and what you learn as you go through life. There will be many mistakes along the way, and lots of “trial and error” as you begin to discover just what it is that will make your improve ideas really work, and also develop their own sound as well.
I know that since I had to learn on my own, and also learned from great improvisers, I was able to almost immediately acquire the kind of approach that was a “natural” one when it came to coming up with new ideas. Maybe it’s the fact that these players who inspired me so much were great improvisers as well was what “fed” my desire and ability to do so much improve on my own…I’ll never be totally sure, but when I was just starting out, I was so excited about the guitar, that I literally used to “dream” up licks on the way from school for example, that I just couldn’t wait to get home and try! It’s still basically that way with me, only the guitar has now become a “complete language” with which I can express myself, and I no longer feel or hear any boundaries at all between my feelings and what my fingers end up expressing for me.
So, as my students, and as my fellow guitarists, I certainly hope these points hit “home” for you, and that you always will try to achieve new and different things when you need to come up with fresh ideas on the guitar. It’s the only way you’ll ever truly develop your own style, especially one that is absolutely recognizable as the one and only you! Good luck!