Use literature!

Hi. I add a nice trick I use:

when studying a piece of literature, be it an important one or a simple small one just take a small fragment of it (1-4 bars) and make it yours:

- first of all commit it to memory
- then transpose it in many (if not all the 12) keys
- then start improvising using that fragment as a guidance but changing the rhytmh for example (but keeping the chords), or changing the chords (and keeping the rhythm), or changing the voicing (make it chordal if it was polyphonic), ... and so on

Of course you should choose a fragment that YOU LIKE and that has some interest from at least one of the following points: rhythm, harmony, polyphony (voicing).

This is a nice way to expand your improvisation vocabulary and to "learn something from the masters", since the fragment comes from a composition YOU LIKE.

Removing the need for the score

Here I can tell you a trick that helps starting getting rid of a score.

Improvisers do not usually need a score, may be sometimes they have just one small piece of paper where someone wrote a melody on which to improvise.

So a nice and rewarding exercice is to do the following: take a score that for you is simple (so you can focus better on what you do) and just read the left hand from the score while improvising the right hand (or the pedals if you are at the organ).

I think the best way to do this is to do a copy of the score and then remove the right hand (in XXI century this is easily done by scanning - image editing - printing; anyway also XX century way is ok...). In this way you are not distracted by the original version.

Start with some "chords composition", where you have a chord for every number of bars (like a mozart Rondò for example) and then try with more counterpoint...

This is just in advice: you should make it work for yourself.

You can take also an heavy metal guitar riff and work on it: this sounds impressive on the organ. I did this with Metallica's Battery: just try!