P.J. Harvey, with Live and Veruca Salt, Wednesday, August 23, at Red Rocks, is a rarity in contemporary pop music: an artist whose integrity and love of creative risk are virtually unassailable. As demonstrated by recordings such as Rid of Me and last year's thrilling To Bring You My Love, Harvey is restless and ambitious, and she's confident enough to take listeners along with her into the uncharted territory she loves to explore. While she's not dismissive of commercial considerations (hell, she's got a cut on the Batman Forever soundtrack), she is more concerned with lyrical truth-telling, musical adventurousness and her notably dark and probing vocals than with becoming the next big alt-babe. And thank goodness for that.