Excellent! Based on felser's response to Thom I had guessed the altoist in #4, but was too lazy to sleuth/verify and it's too early in the month for that anyway. Don't mind reading the IDs...not really spoilers because I wasn't going to get them; Elvin-ness of #2 and Dolphy-ism of #3 not enough to narrow down the candidates.
FWIW I enjoy the semi-non-quasi jazz excursions.
[Added] Based on Jim's ID, #4 must be this. Weirdly, that's from a recording I recently came very close to buying, but held off on because I prefer the altoist's earlier work. 🙄
In the "minimalist" area, Marion Brown collaborated with Harold Budd. I think the first recording of Budd's Bismillahi 'Rahmani 'Rrahim is on MB's Vista (a personal favorite album on which Budd performed). And Brown played on Budd's The Pavilion of Dreams album. See for instance https://newdirectionsinmusic.substack.com/p/harold-budd-marion-brown-and-the