I kind of feel that the instrumental pieces (be they the epic orchestral kind or the other type(s) I have found myself enjoying ... I think I could partially blame certain computer games from the second half of nineties for the latter) fit what I am generally using the playlist for best. I am most often listening music as a background when I am doing something a bit more mechanical, such as drawing (not so much as a mood-setter, but rather somewhat independently). Helps with focusing on the task...
(I've also done the opposite in the past - drawing to keep my focus on audible input. Something about the optimal level of occupation, I suppose.)

I recall about TSFH and audiomachine, yes... (I also recall Ashgan actually commenting on your choice to go with audiomachine's tracks for your characters, and approving of it.) I already did go over TSFH's music a while back - a significant fraction of it, in any case; I am positive I probably still missed some, though. I haven't gone over audiomachine's yet, though, even if do have some of their tracks (probably over half of which are there exactly because you have linked those in the past). Brand X Music and Immediate Music and Ethos Music I have heard of, but not really looked into yet; Michael Riske doesn't ring a bell, so he's perhaps completely new to me. Halo and Chrisis Core's music is likewise new to me, since I've only played very little of the former (don't own it myself) and none of the latter.
*mutters something vague over videogames* 
Thanks, in any case; I will be finding a few playlists and sorting through them as I do other things (as I typically do in these instances).

[@The New Yorker]: Still waiting for your computer to be fixed?