After 30 years of piano improvision I have realised that most jazz pianists carefully work out most aspects of what they play, harmony, tune and rythm. This makes for a completely reproducable performance and gives us the slick CD productions and performances we have become used to.
Listen to the various takes of 'Kind of Blue' and you will hear identical solos everytime. Is this improvisation?
On this site you can download some samples of my completely spontaneous improvisation. Often done in the middle of the night without any planning; one-offs never to be repeated.
10 audio CDs for pianists wanting to learn jazz: soon available for download as MP3.