The four albums you've named all fall into the "early" King Crimson, which as you've noticed by now went through a lot of changes. King Crimson continued to change and evolve, but one thing they've always done is keep both a heavy side and a light side. Robert Fripp clearly likes to wail and scream sometimes (via guitar of course) but he also has a knack for creating beautiful, haunting melodies.
I suggest trying the 80's version of the band next, which will lead you nicely into the more recent stuff which gets even more psychotic. Start with Discipline, the initial offering from the Fripp-Belew-Levin-Bruford band. This band was originally going to be called Discipline, but at some point Fripp decided that it was "worthy" of the name King Crimson, and the band was reborn. This band had two more albums, Beat, and Three of a Perfect Pair, which are similar in sound, but each gets a bit more adventurous within the established style. I like all three of them nearly equally, but some KC fans have some problems with the second and third offerrings.
Starting with the 90's stuff (THRAK), they kinda lost me, so I can't advise you from that point forward. I have the DVD from that period, Deja Vrooom, and it's amazing, but it didn't really lead me into the studio work from that band. Fripp called that band "the double trio" as it had two guitarists, two drummers, and two bass/stick players.