If you had to teach someone how to do this what would you tell them? What are you thinking about? Specifically in terms of harmony? If you had to just break down the first minute of what you did... sounds like Scriabin. Do you have a picked out chord progression or something or are you picking them out as you go? Is there something you're looking at while doing, perhaps an existing score?
Call of The Hundred Islands is great, would benefit hugely from a nicer recording set up imo. Love the composition but the recording setup kind of reminded me of those Art Tatum records, the recording quality leaves something to be desired. But the recording quality is part of what makes those recordings great, maybe something similar is going on with your recording, however definitely curious what it'd sound like mic'ed by a pro. I haven't been able to figure that out either.
The second paragraph is the easier to answer. The recording was made with a tape recorder twenty years ago then written to a CD, so no, the quality is not optimal. I suppose I should really make better recordings of all my old compositions but so far I have been too lazy.
If you had to teach someone how to do this what would you tell them?
That is highly dependent on the individual. I have only attempted it twice, the first being surprisingly successful but the second less so. It isn't like learning and playing pieces, where a task is clearly defined over a short time period. It is a lifelong creative habit which takes a long time, sometimes decades, to acquire and which never stops developing and changing. It is easier to say what I would not do, and that is to tell somebody what notes to play. That is the fatal mistake in all the tutorials on the internet. The first objective would be to get a flow going, exactly what idiom and what notes don't matter. There are numerous ways of approaching this, depending on the individual's taste in music, what sounds he or she likes, lots of possibilities. You are dealing with complete artistic freedom and an infinity of choices. Many people trained in orthodox fashion, even to a brilliant level, perhaps more so the accomplished ones, find complete freedom impossibly daunting. Therefore I would probably place some sort of arbitrary restriction to get them going until a flow became second nature. Exactly what that would be depends on the person. No use forcing someone to play imitation baroque on three scales if it isn't to their taste.
What are you thinking about?
The seemingly flippant but true answer is "not a lot", at least not in the sense of completely conscious, logical volition. I usually answer this question with a mathematical analogy. It's a bit like chaotic processes such as pendulums and other algorithmic pattern generators and functions. The idea is to reach that rather special state wherein an endless stream of unpredictable yet interesting events occurs. Too few mental feedback loops result in fully determined, stable, clever improvisation which mostly lacks life and interest. Too much feedback results in instability and apparent randomness. These extremes are equally dull but in different ways. I hasten to add that these thoughts, as far as I know, are original and might make little sense to musicians.
Specifically in terms of harmony?
That is difficult to answer because harmony is just one of a number of musical properties, each of which provides feedback to all the others. Of course, over the years I have assimilated a large number of note combinations, just like I have found very many physical techniques and haptic associations. I was no different to anybody learning music in terms of these components of playing, it's what everyone does. Hearing music as a series of chords is an option, and like all creative options can be indulged or restricted depending on the music.
Is there something you're looking at while doing, perhaps an existing score?
No, never, I can be definite about that one.
Do you have a picked out chord progression or something or are you picking them out as you go?
I hardly ever think in terms of either chords or chord progressions for the reason that I have never understood why any particular chord should imply the following one. My poor old teacher did his best with me but gave up in the end. I simply do not understand theory at all, put it that way.
I am sorry if all this offers little practical explanation. I rarely know what I am doing at the best of times. Had I been any good at classical or jazz I probably wouldn't be playing this sort of stuff at all.