I once had a student ask me how to improvise for more than a minute or two. He had some trouble keeping the music going for longer periods of time.
I told him that the problem wasn’t with knowing enough material. He already knew how to play a few chords. It was his attitude – that trying to come up with something was what was blocking the creative flow. This can be hard to understand. After all, aren’t we supposed to “come up” with something? Isn’t that what invention is all about? In a word – no.
Being present is the key to allowing the music to unfold. Blocks happen because we are not present at the moment. The minute you start thinking of anything else (actually, the minute you start thinking) is when the critical voice comes in. Improvisation is spontaneous creation within limits. Successful improvisations don’t happen out of thin air.
Certain decisions are made AT THE BEGINNING. For example, I may find myself playing a D minor chord. This may happen completely at random with no prior decision being made. I can, in fact, gravitate towards a particular sound. However, as I am playing this chord, I look down at the keyboard and it occurs to me that this is a D minor chord. I know that if
I start with this chord I could play improvisation in the mode of D Dorian. I have all the chords of this mode to use.
Now the game is an improvisation in the key of D Dorian. I could stray and go into different tonalities, but I have made a preliminary decision that the improvisation will be in D Dorian. This frees me up by allowing me to focus on just a few chords. Now, I can play for as long as I like.
There is no secret to keeping an improvisation going. Keeping it sounding fresh is another thing. I could play for hours if I wanted to use just the chords in the D Dorian mode, but, I think I would want to stop playing when I became bored.
The secret to fresh improvisations is always to let the music tell you where it wants to go. You need to step out of the way and allow the music to happen.