I've read Outram's blog, and I don't agree with his description of the proccess (which means that there isn't a universal proccess of thought).
For me, I experience several levels of awareness. At the same time, I think about (in no particular order):
- The note that I'm playing in that precise moment, if any. Its timbre, how it feels with the music, and any other consideration (if I should vibrate it, how much, or should I mute it, make it stacatto....)
- What's coming next, in terms of feel, melodic direction, dynamics....(if I don't feel stuck, normally this proccess is just about planning a line, maybe one or two bars ahead). Here I would put also what came before, to give cohesion to the line.
- Awareness of the theoretical underlying harmonic structure (i.e: what the &%$ changes are and what bar I'm in?)
- Awareness of one (or more) accompanying instruments rythm and/or harmony, dynamics, etc. This depends really, but I don't know on what. Sometimes I'm able to hear clearly two or three instruments and in some way assimilate what they're doing, and respond accordingly. Some other times, I'm just able to feel the overall sound, but can concentrate on one instrument at a time.
- Melodic content. Here I think about what scale choices would sound "right" based on the harmony. In the former category "what's coming next", the melodic content is based purely on what feels right just by ear, without any analytical proccess.
- If I have some spare neurons, my brain would start to wander any kind of weird things, but that doesn't happen much often lol,
just my 2 cents