Warthur
This EP from King Crimson does the same job for The Power To Believe album as VROOOM did for THRAK - act as a preview of the material being worked on for the album and a general indication of where King Crimson's heads were at. In this case, the answer to the latter is "favourably impressed by the young padawans Tool and King Crimson", since the heavy metal-influenced prog of those bands influences the title track here (yet another King Crimson rumination about the process of making music itself).
On the whole, it's a pretty decent EP, reflecting what the band were concentrating on at the time - namely, dividing their attentions between workshopping material for The Power To Believe (they weren't going to make the same mistake they made with The ConstruKction of Light and go into the studio without a set of material which had received careful refinement and polishing in the leadup to it), and revisiting the material from The ConstruKction of Light to tease out its better aspects. (The version of Larks' Tongues In Aspic Part IV here is excellent, and knocks the version on ConstruKction of Light out cold.)