The Red Hot Organization’s eighth compilation Offbeat: A Red Hot Soundtrip — the proceeds of which benefit AIDS groups — explores post-rock with the same agility as 1995’s Red Hot + Bothered did the indie scene. The record morphs from trip-hoppy rhythms to ambient echoes to trance. The one blemish is Amiri Baraka’s wanna-Beat poetry, which would have been better left to Gil Scott-Heron. Otherwise, Skylab, Laika, and DJs Krush and Spooky spin rave-worthy sounds. A-