Led by genius guitarist Robert Fripp, prog-rock icons King Crimson have changed personnel and altered styles often, but at core they remain sorcerers who strive to stretch the parameters of whatever mode they’re engaging. The band’s massive catalog abounds with songs of poignant beauty and harrowing savagery, of maniacal, subtly shifting reiterations of trance-inducing melodies and rhythms. Tonight, KC legends Fripp, Mel Collins, and Tony Levin head a three-drummer lineup that reportedly will cover material spanning 1969 to 2011. (Moore Theatre, 1932 Second Ave, stgpresents.org, 7:30 pm, $37–$350, all ages)