Not that there is anything wrong with playing Koln as piece of 'classical' music but the whole meaning of the music is changed as soon as it is reproduced like this. I guess the reason is that you can't learn to improvise by playing other peoples improvisations. In fact I don't know many jazz pianists who would actually learn one of these type transcriptions note for note as a learning tool. I think having a broader knowledge of jazz harmony and being able to feel how the music rhythmically flows and then doing you're own thing on that particular piece or perhaps even an orginal composition or improvisation based on it, would be much more beneficial from a musical standpoint.fwiw of course.

I would analyze his voicings in the places that caught my ear and then transpose those little sections to all twelve keys. What they are good for is to check out the voicings and lh accompaniment Keith uses. I've worked on sections of Fats Waller and other stride type pianists transcriptions just to get more of that particular vocabulary but never worked on it like I would learning a Classical piece of music. With these kind of transcriptions I would let your ear be the guide as you mentioned. But you could probably get pretty danged close by just using the music as a guide as to the notes to be played and then just mimic the rhythm and timing by ear. I can tell that whoever did the transcription was working hard to make it exactly faithful to how it was played. But the transcription itself is a horror show. The music didn't SOUND all that hard on that first part, which is why I even dared buy the book.

Keith jarrett transcription